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LNF: TRANSOPTSTELL. Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados (2022-2025)

2026-04-27T08:29:59Z

Jlvelasco: corregida referencia

== LNF - Nationally funded project ==

[[File:Logos MinFederAEI.jpg|thumb|right|300px|Ayuda PID2021-123175NB-I00 financiada por MICIU/AEI/10.13039/501100011033.]]

'''Title''': '''Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados '''

'''Reference''': PID2021-123175NB-I00

'''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2021-2023

'''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2021

'''Area/subarea (Área temática / subárea)''': Ciencias Físicas / Física de partículas y nuclear.

'''Principal Investigator(s)''': [https://orcid.org/0000-0001-8510-1422 José Luis Velasco] e [https://orcid.org/0000-0003-3118-3463 Iván Calvo]

'''Project type''': Proyecto individual / coordinado

'''Start-end dates''': 01/09/2022 - 31/08/2027 (extended till 28/02/2026)

'''Financing granted (direct costs)''': 105.000 €

== Description of the project ==

Los conceptos más avanzados para un reactor de fusión basado en confinamiento magnético son el tokamak y el stellarator. En ambos casos, se emplean campos magnéticos con superficies magnéticas toroidales anidadas para confinar una mezcla caliente de electrones e iones de isótopos del hidrógeno. La configuración magnética del tokamak tiene simetría axial, lo cual garantiza un buen confinamiento. Sin embargo, parte de su campo magnético se genera mediante una gran corriente toroidal en el interior del plasma, y esto plantea ciertos problemas. Por un lado, esta corriente puede dar lugar a inestabilidades MHD. Por el otro, la necesidad de producir esta corriente de forma inductiva complica la operación en estado estacionario. Los stellarators no tienen estas desventajas, lo cual los hace atractivos como concepto para futuras centrales eléctricas comerciales: puesto que su campo magnético se genera casi completamente mediante bobinas externas, su operación es intrínsecamente estacionaria, y están libres de inestabilidades generadas por las corrientes del plasma. La contrapartida es que su configuración magnética se vuelve tridimensional, y por tanto son más difíciles de diseñar y construir. Es necesario recurrir a la optimización, es decir, al diseño cuidadoso de las bobinas, de modo que la configuración magnética del stellarator cumpla una serie de criterios y tenga un confinamiento de calidad comparable a la del tokamak. Estos criterios pueden incluir bajo transporte neoclásico (causado por la inhomogeneidad del campo magnético y las colisiones entre partículas) y turbulento, corrientes pequeñas dentro de las superficies magnéticas y buen confinamiento de los iones rápidos. Adicionalmente, la tridimensionalidad de la configuración magnética del stellarator hace necesarios teorías y códigos sofisticados para modelar estos procesos de transporte.

Wendelstein 7-X (W7-X) es el primer stellarator grande diseñado mediante optimización, y sus primeras campañas experimentales han sido un gran éxito. Sin embargo, se diseñó hace décadas y hay margen para la mejora, en particular en relación al confinamiento de los iones rápidos y al transporte turbulento. El siguiente paso en la ruta hacia el stellarator reactor debe ser una máquina que esté suficientemente optimizada con respecto a todos los criterios necesarios. El objetivo de este proyecto es contribuir a ese paso llevando la teoría y simulación del transporte en stellarators al nivel de madurez necesario para mejorar decisivamente la explotación experimental y optimización de stellarators. Específicamente:

- Desarrollaremos códigos numéricos que puedan calcular de forma precisa y eficiente el transporte neoclásico de especies térmicas e iones rápidos y la corriente paralela a las superficies magnéticas. Los compararemos con los códigos estándar de la comunidad stellarator y, cuando sea posible, los validaremos mediante comparación con el experimento.

- Mejoraremos y emplearemos códigos girocinéticos para modelar el transporte turbulento de energía, partículas e impurezas (es decir, especies diferentes a los electrones e isótopos de hidrógeno), y validaremos nuestras predicciones en experimentos en W7-X, LHD y TJ- II.

- Usando estas herramientas, mejoraremos las estrategias de optimización de stellarators y produciremos nuevas configuraciones optimizadas con bobinas factibles para dispositivos de nueva generación.

- Extrapolaremos nuestros descubrimientos a escenarios reactor.


== Main results ==
To be completed at the end of the project (taken from the final report)

== Dissemination of project results (peer-reviewed publications and conference presentations) ==
Enter text here


<hr>
[[LNF:Nationally Funded Projects|Back to list of nationally funded projects]]

[[Category:LNF Nationally Funded Projects]]

LNF: FIRESTELL. Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño (2025-2028)

2026-04-27T08:29:31Z

Jlvelasco: añadidos logos

== LNF - Nationally funded project ==

[[File:Logos MinFederAEI.jpg|thumb|right|300px|Ayuda PID2024- 155558OB-I00 financiada por MICIU/AEI/10.13039/501100011033 y por FEDER Una manera de hacer Europa.]]

'''Title''': '''Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño '''

'''Reference''': PID2024-155558OB-I00

'''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2024-2027

'''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2024

'''Area/subarea (Área temática / subárea)''': Ciencias Físicas / Física de partículas y nuclear.

'''Principal Investigator(s)''': [https://orcid.org/0000-0001-8510-1422 José Luis Velasco] e [https://orcid.org/0000-0003-3118-3463 Iván Calvo]

'''Project type''': Proyecto individual / coordinado

'''Start-end dates''': 01/09/2025 - 30/08/2028

'''Financing granted (direct costs)''': 105.000 €

== Description of the project ==

El stellarator presenta una serie de ventajas respecto al tokamak, el otro concepto destacado para ser la base de los reactores de fusión por confinamiento magnético. En ambos casos se utiliza un campo magnético con superficies toroidales anidadas para confinar un plasma formado por electrones y núcleos de isótopos de hidrógeno. Los tokamaks tienen simetría axial y, por tanto, son más sencillos de diseñar y construir, pero la operación de reactores de tipo tokamaks es problemática: dado que la generación de parte del campo magnético confinante del tokamak depende de una corriente inducida en el plasma, la operación continua es más difícil y estos dispositivos son vulnerables frente a inestabilidades de corriente. Los stellarators evitan la necesidad de esta corriente por medio de un campo magnético tridimensional, que es generado por bobinas externas y que ha de ser cuidadosamente diseñado (optimizado, en la terminología habitual) para garantizar un buen confinamiento. En consecuencia, los stellarators son más difíciles de diseñar y construir, pero ofrecen un concepto intrínsecamente estable y de operación continua para plantas de fusión comerciales.

El escalado desde los stellarators actuales a los reactores implica un aumento de tamaño y coste significativo, así como regímenes de plasma inexplorados. Para minimizar los riesgos científicos y económicos, el diseño de los reactores de tipo stellarator ha de apoyarse fuertemente en la teoría y simulaciones numéricas avanzadas capaces de hacer predicciones precisas. El objetivo global de este proyecto es desarrollar y validar herramientas numéricas para resolver desafíos cruciales en el camino hacia los reactores de tipo stellarator, y por lo tanto ayudar a acelerar la llegada de la energía de fusión. El proyecto se organiza en torno a tres tareas generales: (1) optimizar campos magnéticos que puedan ser la base de reactores de tipo stellarator, (2) predecir el comportamiento del plasma confinado por estos campos magnéticos y (3) identificar puntos de diseño (por ejemplo, tamaño e intensidad del campo magnético) físicamente viables para los reactores. Los objetivos generales dentro de cada tarea se resumen a continuación.

(1) Evaluar (y, en su caso, mejorar) el desempeño, desde el punto de vista de la física, de las configuraciones de la familia CIEMAT-QI como candidatas para reactores de tipo stellarator y explorar el potencial de la nueva noción de omnigeneidad a trozos.

(2) Validar ideas teóricas y códigos numéricos (y aplicarlas a problemas no resueltos) sobre dos aspectos críticos de la física de plasmas en reactores stellarator: turbulencia y confinamiento de iones energéticos, y sobre la interacción entre los dos.

(3) Usar modelos simplificados basados en leyes de escala teóricas y empíricas, y ligaduras generales de tecnología de reactores para identificar parámetros de reactores potencialmente viables y para caracterizar sus regímenes de plasma. Aplicar los códigos precisos de la tarea (2) a estos parámetros.

Este proyecto está bien alineado con la hoja de ruta 'European Research Roadmap to the Realisation of Fusion Energy' elaborada por la UE, que está dividida en ocho misiones, y una de las cuales tiene como objetivo llevar el concepto del stellarator a la madurez. Una de las metas en el medio y largo plazo es desarrollar las capacidades requeridas para tomar una decisión sobre la siguiente generación de stellarators en el camino hacia la fusión comercial.


== Main results ==
To be completed at the end of the project (final report)

== Dissemination of project results (peer-reviewed publications and conference presentations) ==
Enter text here

== References ==



<hr>
[[LNF:Nationally Funded Projects|Back to list of nationally funded projects]]

[[Category:LNF Nationally Funded Projects]]

LNF: TRANSOPTSTELL. Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados (2022-2025)

2026-04-27T08:29:10Z

Jlvelasco: añadidos logos

== LNF - Nationally funded project ==

[[File:Logos MinFederAEI.jpg|thumb|right|300px|Ayuda PID2024- 155558OB-I00 financiada por MICIU/AEI/10.13039/501100011033 y por FEDER Una manera de hacer Europa.]]

'''Title''': '''Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados '''

'''Reference''': PID2021-123175NB-I00

'''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2021-2023

'''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2021

'''Area/subarea (Área temática / subárea)''': Ciencias Físicas / Física de partículas y nuclear.

'''Principal Investigator(s)''': [https://orcid.org/0000-0001-8510-1422 José Luis Velasco] e [https://orcid.org/0000-0003-3118-3463 Iván Calvo]

'''Project type''': Proyecto individual / coordinado

'''Start-end dates''': 01/09/2022 - 31/08/2027 (extended till 28/02/2026)

'''Financing granted (direct costs)''': 105.000 €

== Description of the project ==

Los conceptos más avanzados para un reactor de fusión basado en confinamiento magnético son el tokamak y el stellarator. En ambos casos, se emplean campos magnéticos con superficies magnéticas toroidales anidadas para confinar una mezcla caliente de electrones e iones de isótopos del hidrógeno. La configuración magnética del tokamak tiene simetría axial, lo cual garantiza un buen confinamiento. Sin embargo, parte de su campo magnético se genera mediante una gran corriente toroidal en el interior del plasma, y esto plantea ciertos problemas. Por un lado, esta corriente puede dar lugar a inestabilidades MHD. Por el otro, la necesidad de producir esta corriente de forma inductiva complica la operación en estado estacionario. Los stellarators no tienen estas desventajas, lo cual los hace atractivos como concepto para futuras centrales eléctricas comerciales: puesto que su campo magnético se genera casi completamente mediante bobinas externas, su operación es intrínsecamente estacionaria, y están libres de inestabilidades generadas por las corrientes del plasma. La contrapartida es que su configuración magnética se vuelve tridimensional, y por tanto son más difíciles de diseñar y construir. Es necesario recurrir a la optimización, es decir, al diseño cuidadoso de las bobinas, de modo que la configuración magnética del stellarator cumpla una serie de criterios y tenga un confinamiento de calidad comparable a la del tokamak. Estos criterios pueden incluir bajo transporte neoclásico (causado por la inhomogeneidad del campo magnético y las colisiones entre partículas) y turbulento, corrientes pequeñas dentro de las superficies magnéticas y buen confinamiento de los iones rápidos. Adicionalmente, la tridimensionalidad de la configuración magnética del stellarator hace necesarios teorías y códigos sofisticados para modelar estos procesos de transporte.

Wendelstein 7-X (W7-X) es el primer stellarator grande diseñado mediante optimización, y sus primeras campañas experimentales han sido un gran éxito. Sin embargo, se diseñó hace décadas y hay margen para la mejora, en particular en relación al confinamiento de los iones rápidos y al transporte turbulento. El siguiente paso en la ruta hacia el stellarator reactor debe ser una máquina que esté suficientemente optimizada con respecto a todos los criterios necesarios. El objetivo de este proyecto es contribuir a ese paso llevando la teoría y simulación del transporte en stellarators al nivel de madurez necesario para mejorar decisivamente la explotación experimental y optimización de stellarators. Específicamente:

- Desarrollaremos códigos numéricos que puedan calcular de forma precisa y eficiente el transporte neoclásico de especies térmicas e iones rápidos y la corriente paralela a las superficies magnéticas. Los compararemos con los códigos estándar de la comunidad stellarator y, cuando sea posible, los validaremos mediante comparación con el experimento.

- Mejoraremos y emplearemos códigos girocinéticos para modelar el transporte turbulento de energía, partículas e impurezas (es decir, especies diferentes a los electrones e isótopos de hidrógeno), y validaremos nuestras predicciones en experimentos en W7-X, LHD y TJ- II.

- Usando estas herramientas, mejoraremos las estrategias de optimización de stellarators y produciremos nuevas configuraciones optimizadas con bobinas factibles para dispositivos de nueva generación.

- Extrapolaremos nuestros descubrimientos a escenarios reactor.


== Main results ==
To be completed at the end of the project (taken from the final report)

== Dissemination of project results (peer-reviewed publications and conference presentations) ==
Enter text here


<hr>
[[LNF:Nationally Funded Projects|Back to list of nationally funded projects]]

[[Category:LNF Nationally Funded Projects]]

File:Logos MinFederAEI.jpg

2026-04-27T08:25:15Z

Jlvelasco:

Omnigeneity

2026-02-09T10:55:17Z

Jlvelasco:

Omnigeneity (or omnigenity) is a property of the vacuum magnetic field such that the mean radial collisionless guiding center magnetic drift is zero.
Thus, in a perfectly omnigenous field, all collisionless trajectories are confined.
<ref>D.A. Garren and A.H. Boozer, ''Existence of quasihelically symmetric stellarators'', [[doi:10.1063/1.859916|Phys. Fluids B 3 (1991) 2822]]</ref>
<ref>M. Landreman and P.J. Catto, ''Omnigenity as generalized quasisymmetry'', [[doi:10.1063/1.3693187|Phys. Plasmas '''19''' (2012) 056103]]</ref>

== See also ==
* [[Stellarator]]
* [[Quasisymmetry]]
* [[Piecewise_omnigeinity]]

== References ==
<references />

Piecewise Omnigeneity

2026-02-09T10:54:48Z

Jlvelasco:

Piecewise omnigenity is a property of the magnetic field such that the mean radial collisionless guiding center magnetic drift is zero. It consists on the property of [[omnigeneity]] being fulfilled piecewisely on the flux surface of the stellarator.

Piecewise Omnigeneity

2026-02-09T10:53:42Z

Jlvelasco: Created page with "Piecewise omnigenity is a property of the magnetic field such that the mean radial collisionless guiding center magnetic drift is zero. It consists on the property of omnigenity being fulfilled piecewisely on the flux surface of the stellarator."

Piecewise omnigenity is a property of the magnetic field such that the mean radial collisionless guiding center magnetic drift is zero. It consists on the property of omnigenity being fulfilled piecewisely on the flux surface of the stellarator.

LNF: TRANSOPTSTELL. Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados (2022-2025)

2025-10-07T13:26:37Z

Jlvelasco: Created page with "== LNF - Nationally funded project == '''Title''': '''Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados ''' '''Reference''': PID2021-123175NB-I00 '''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2021-2023 '''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2021 '''Area/subarea (Área temática / subárea)''': Ciencias..."

== LNF - Nationally funded project ==

'''Title''': '''Simulaciones de transporte en plasmas confinados en stellarators y aplicaciones al diseño de dispositivos optimizados '''

'''Reference''': PID2021-123175NB-I00

'''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2021-2023

'''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2021

'''Area/subarea (Área temática / subárea)''': Ciencias Físicas / Física de partículas y nuclear.

'''Principal Investigator(s)''': [https://orcid.org/0000-0001-8510-1422 José Luis Velasco] e [https://orcid.org/0000-0003-3118-3463 Iván Calvo]

'''Project type''': Proyecto individual / coordinado

'''Start-end dates''': 01/09/2022 - 28/02/2026

'''Financing granted (direct costs)''': 105.000 €

== Description of the project ==

Los conceptos más avanzados para un reactor de fusión basado en confinamiento magnético son el tokamak y el stellarator. En ambos casos, se emplean campos magnéticos con superficies magnéticas toroidales anidadas para confinar una mezcla caliente de electrones e iones de isótopos del hidrógeno. La configuración magnética del tokamak tiene simetría axial, lo cual garantiza un buen confinamiento. Sin embargo, parte de su campo magnético se genera mediante una gran corriente toroidal en el interior del plasma, y esto plantea ciertos problemas. Por un lado, esta corriente puede dar lugar a inestabilidades MHD. Por el otro, la necesidad de producir esta corriente de forma inductiva complica la operación en estado estacionario. Los stellarators no tienen estas desventajas, lo cual los hace atractivos como concepto para futuras centrales eléctricas comerciales: puesto que su campo magnético se genera casi completamente mediante bobinas externas, su operación es intrínsecamente estacionaria, y están libres de inestabilidades generadas por las corrientes del plasma. La contrapartida es que su configuración magnética se vuelve tridimensional, y por tanto son más difíciles de diseñar y construir. Es necesario recurrir a la optimización, es decir, al diseño cuidadoso de las bobinas, de modo que la configuración magnética del stellarator cumpla una serie de criterios y tenga un confinamiento de calidad comparable a la del tokamak. Estos criterios pueden incluir bajo transporte neoclásico (causado por la inhomogeneidad del campo magnético y las colisiones entre partículas) y turbulento, corrientes pequeñas dentro de las superficies magnéticas y buen confinamiento de los iones rápidos. Adicionalmente, la tridimensionalidad de la configuración magnética del stellarator hace necesarios teorías y códigos sofisticados para modelar estos procesos de transporte.

Wendelstein 7-X (W7-X) es el primer stellarator grande diseñado mediante optimización, y sus primeras campañas experimentales han sido un gran éxito. Sin embargo, se diseñó hace décadas y hay margen para la mejora, en particular en relación al confinamiento de los iones rápidos y al transporte turbulento. El siguiente paso en la ruta hacia el stellarator reactor debe ser una máquina que esté suficientemente optimizada con respecto a todos los criterios necesarios. El objetivo de este proyecto es contribuir a ese paso llevando la teoría y simulación del transporte en stellarators al nivel de madurez necesario para mejorar decisivamente la explotación experimental y optimización de stellarators. Específicamente:

- Desarrollaremos códigos numéricos que puedan calcular de forma precisa y eficiente el transporte neoclásico de especies térmicas e iones rápidos y la corriente paralela a las superficies magnéticas. Los compararemos con los códigos estándar de la comunidad stellarator y, cuando sea posible, los validaremos mediante comparación con el experimento.

- Mejoraremos y emplearemos códigos girocinéticos para modelar el transporte turbulento de energía, partículas e impurezas (es decir, especies diferentes a los electrones e isótopos de hidrógeno), y validaremos nuestras predicciones en experimentos en W7-X, LHD y TJ- II.

- Usando estas herramientas, mejoraremos las estrategias de optimización de stellarators y produciremos nuevas configuraciones optimizadas con bobinas factibles para dispositivos de nueva generación.

- Extrapolaremos nuestros descubrimientos a escenarios reactor.


== Principales publicaciones ==
<references />


<hr>
[[LNF:Nationally Funded Projects|Back to list of nationally funded projects]]

[[Category:LNF Nationally Funded Projects]]

LNF: FIRESTELL. Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño (2025-2028)

2025-10-07T13:22:47Z

Jlvelasco:

== LNF - Nationally funded project ==

'''Title''': '''Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño '''

'''Reference''': PID2024-155558OB-I00

'''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2024-2027

'''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2024

'''Area/subarea (Área temática / subárea)''': Ciencias Físicas / Física de partículas y nuclear.

'''Principal Investigator(s)''': [https://orcid.org/0000-0001-8510-1422 José Luis Velasco] e [https://orcid.org/0000-0003-3118-3463 Iván Calvo]

'''Project type''': Proyecto individual / coordinado

'''Start-end dates''': 01/09/2025 - 30/08/2028

'''Financing granted (direct costs)''': 105.000 €

== Description of the project ==

El stellarator presenta una serie de ventajas respecto al tokamak, el otro concepto destacado para ser la base de los reactores de fusión por confinamiento magnético. En ambos casos se utiliza un campo magnético con superficies toroidales anidadas para confinar un plasma formado por electrones y núcleos de isótopos de hidrógeno. Los tokamaks tienen simetría axial y, por tanto, son más sencillos de diseñar y construir, pero la operación de reactores de tipo tokamaks es problemática: dado que la generación de parte del campo magnético confinante del tokamak depende de una corriente inducida en el plasma, la operación continua es más difícil y estos dispositivos son vulnerables frente a inestabilidades de corriente. Los stellarators evitan la necesidad de esta corriente por medio de un campo magnético tridimensional, que es generado por bobinas externas y que ha de ser cuidadosamente diseñado (optimizado, en la terminología habitual) para garantizar un buen confinamiento. En consecuencia, los stellarators son más difíciles de diseñar y construir, pero ofrecen un concepto intrínsecamente estable y de operación continua para plantas de fusión comerciales.

El escalado desde los stellarators actuales a los reactores implica un aumento de tamaño y coste significativo, así como regímenes de plasma inexplorados. Para minimizar los riesgos científicos y económicos, el diseño de los reactores de tipo stellarator ha de apoyarse fuertemente en la teoría y simulaciones numéricas avanzadas capaces de hacer predicciones precisas. El objetivo global de este proyecto es desarrollar y validar herramientas numéricas para resolver desafíos cruciales en el camino hacia los reactores de tipo stellarator, y por lo tanto ayudar a acelerar la llegada de la energía de fusión. El proyecto se organiza en torno a tres tareas generales: (1) optimizar campos magnéticos que puedan ser la base de reactores de tipo stellarator, (2) predecir el comportamiento del plasma confinado por estos campos magnéticos y (3) identificar puntos de diseño (por ejemplo, tamaño e intensidad del campo magnético) físicamente viables para los reactores. Los objetivos generales dentro de cada tarea se resumen a continuación.

(1) Evaluar (y, en su caso, mejorar) el desempeño, desde el punto de vista de la física, de las configuraciones de la familia CIEMAT-QI como candidatas para reactores de tipo stellarator y explorar el potencial de la nueva noción de omnigeneidad a trozos.

(2) Validar ideas teóricas y códigos numéricos (y aplicarlas a problemas no resueltos) sobre dos aspectos críticos de la física de plasmas en reactores stellarator: turbulencia y confinamiento de iones energéticos, y sobre la interacción entre los dos.

(3) Usar modelos simplificados basados en leyes de escala teóricas y empíricas, y ligaduras generales de tecnología de reactores para identificar parámetros de reactores potencialmente viables y para caracterizar sus regímenes de plasma. Aplicar los códigos precisos de la tarea (2) a estos parámetros.

Este proyecto está bien alineado con la hoja de ruta 'European Research Roadmap to the Realisation of Fusion Energy' elaborada por la UE, que está dividida en ocho misiones, y una de las cuales tiene como objetivo llevar el concepto del stellarator a la madurez. Una de las metas en el medio y largo plazo es desarrollar las capacidades requeridas para tomar una decisión sobre la siguiente generación de stellarators en el camino hacia la fusión comercial.


== Principales publicaciones ==
<references />


<hr>
[[LNF:Nationally Funded Projects|Back to list of nationally funded projects]]

[[Category:LNF Nationally Funded Projects]]

LNF: FIRESTELL. Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño (2025-2028)

2025-10-07T13:21:02Z

Jlvelasco: Created page with "== LNF - Nationally funded project == '''Title''': '''Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño ''' '''Reference''': PID2024-155558OB-I00 '''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2024-2027 '''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2024 '''Area/..."

== LNF - Nationally funded project ==

'''Title''': '''Física de los reactores de fusión de tipo stellarator: optimización del campo magnético, predicción de escenarios de plasma e identificación de puntos de diseño '''

'''Reference''': PID2024-155558OB-I00

'''Programme and date''': Plan Estatal de Investigación Científica, Técnica y de Innovación 2024-2027

'''Programme type (Modalidad de proyecto)''': Proyectos de Generación de Conocimiento 2024

'''Area/subarea (Área temática / subárea)''': Ciencias Físicas / Física de partículas y nuclear.

'''Principal Investigator(s)''': [https://orcid.org/0000-0000-0000-0000 José Luis Velasco] e [https://orcid.org/0000-0000-0000-0000 Iván Calvo]

'''Project type''': Proyecto individual / coordinado

'''Start-end dates''': 01/09/2025 - 30/08/2028

'''Financing granted (direct costs)''': 105.000 €

== Description of the project ==

El stellarator presenta una serie de ventajas respecto al tokamak, el otro concepto destacado para ser la base de los reactores de fusión por confinamiento magnético. En ambos casos se utiliza un campo magnético con superficies toroidales anidadas para confinar un plasma formado por electrones y núcleos de isótopos de hidrógeno. Los tokamaks tienen simetría axial y, por tanto, son más sencillos de diseñar y construir, pero la operación de reactores de tipo tokamaks es problemática: dado que la generación de parte del campo magnético confinante del tokamak depende de una corriente inducida en el plasma, la operación continua es más difícil y estos dispositivos son vulnerables frente a inestabilidades de corriente. Los stellarators evitan la necesidad de esta corriente por medio de un campo magnético tridimensional, que es generado por bobinas externas y que ha de ser cuidadosamente diseñado (optimizado, en la terminología habitual) para garantizar un buen confinamiento. En consecuencia, los stellarators son más difíciles de diseñar y construir, pero ofrecen un concepto intrínsecamente estable y de operación continua para plantas de fusión comerciales.

El escalado desde los stellarators actuales a los reactores implica un aumento de tamaño y coste significativo, así como regímenes de plasma inexplorados. Para minimizar los riesgos científicos y económicos, el diseño de los reactores de tipo stellarator ha de apoyarse fuertemente en la teoría y simulaciones numéricas avanzadas capaces de hacer predicciones precisas. El objetivo global de este proyecto es desarrollar y validar herramientas numéricas para resolver desafíos cruciales en el camino hacia los reactores de tipo stellarator, y por lo tanto ayudar a acelerar la llegada de la energía de fusión. El proyecto se organiza en torno a tres tareas generales: (1) optimizar campos magnéticos que puedan ser la base de reactores de tipo stellarator, (2) predecir el comportamiento del plasma confinado por estos campos magnéticos y (3) identificar puntos de diseño (por ejemplo, tamaño e intensidad del campo magnético) físicamente viables para los reactores. Los objetivos generales dentro de cada tarea se resumen a continuación.

(1) Evaluar (y, en su caso, mejorar) el desempeño, desde el punto de vista de la física, de las configuraciones de la familia CIEMAT-QI como candidatas para reactores de tipo stellarator y explorar el potencial de la nueva noción de omnigeneidad a trozos.

(2) Validar ideas teóricas y códigos numéricos (y aplicarlas a problemas no resueltos) sobre dos aspectos críticos de la física de plasmas en reactores stellarator: turbulencia y confinamiento de iones energéticos, y sobre la interacción entre los dos.

(3) Usar modelos simplificados basados en leyes de escala teóricas y empíricas, y ligaduras generales de tecnología de reactores para identificar parámetros de reactores potencialmente viables y para caracterizar sus regímenes de plasma. Aplicar los códigos precisos de la tarea (2) a estos parámetros.

Este proyecto está bien alineado con la hoja de ruta 'European Research Roadmap to the Realisation of Fusion Energy' elaborada por la UE, que está dividida en ocho misiones, y una de las cuales tiene como objetivo llevar el concepto del stellarator a la madurez. Una de las metas en el medio y largo plazo es desarrollar las capacidades requeridas para tomar una decisión sobre la siguiente generación de stellarators en el camino hacia la fusión comercial.


== Principales publicaciones ==
<references />


<hr>
[[LNF:Nationally Funded Projects|Back to list of nationally funded projects]]

[[Category:LNF Nationally Funded Projects]]

LNF:Organization

2023-03-17T07:27:41Z

Jlvelasco: /* Fusion Theory Unit */

== Laboratorio Nacional de Fusión ==

Asociación [[Euratom]]-[[CIEMAT]]: see [[Laboratorio Nacional de Fusión]].

Contact information is also available via the [http://www.ciemat.es/cargarFichaOrganizacion.do?idOrganizacion=F00 CIEMAT website]

The telephone numbers listed below are extensions; to call from outside the laboratory, dial: +34-91346xxxx, where xxxx is the extension. (When using 4-digit dialing from inside the laboratory: substitute any initial "0" by a "7".)

[https://www.gruptelecom.com/wp-content/uploads/2018/07/Manual_Unify_CP-200.pdf IP-phone manual]

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Hidalgo Vera, Carlos, Director || 6498 ||
|-
|}

=== TJ-II Experimental Division ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Alonso de Pablo, Arturo, Head Investigator || 6293 || 362401
|-
| Baciero Adrados, Alfonso || 6493 || 362601
|-
| Blanco Villareal, Emilio J. || 7904 ||
|-
| de la Cal Heusch, Eduardo || 6317 ||
|-
| de la Luna Gargantilla, Elena || 0849 || 362937
|-
| Carralero Ortiz, Daniel || 7852 || 362263
|-
| Castro Rojo, Rodrigo || 6419 ||
|-
| Fontdecaba Climent, Jose María || 6642 ||
|-
| García Cortés, Mª. Isabel || 6515 || 362625
|-
| Hernanz Hernanz, Francisco J. || 6641 ||
|-
| López Miranda, Belén || || 362093
|-
| McCarthy, Kieran Joseph || 0846 || 362934
|-
| Medina Yela, Francisco || 0847 || 362935
|-
| Ochando Garcia, Mª. Antonia || 6462 ||
|-
| de Pablos Hernández, Jose Luis || 6374 ||
|-
| Panadero Álvarez, Nerea || 6642 || 362781
|-
| Pastor Díaz, Ignacio || 6324 ||
|-
| Pastor Santos, Carmen || || 362564
|-
| Rattá Gutiérrez, Giuseppe A. || 7917 ||
|-
| Rodríguez Fernández, Mª. Carmen || 2611 ||
|-
| [[User:Admin|van Milligen, Boudewijn]] || 6379 || 362482
|-
| Vega Sánchez, Jesús Antonio || 6474 ||
|}

=== TJ-II Operation Division===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Estrada García, Teresa, Head Investigator || 6369 ||
|-
| Alegre Castro, Daniel || 0914 ||
|-
| Cappa Ascasíbar, Alvaro || 6646 Sala de Control ECRH 6828 || 362784
|-
| Cebrián Ruiz, Luis A. || 6338 ||
|-
| Chamorro Lastra, Manuel || 6641 ||
|-
| García Gomez, Raúl || 6641 ||
|-
| Guasp Pérez, Jose || 6510 ||
|-
| Guisse Arévalo, Víctor H. || 6285 ||
|-
| Liniers Vazquez, Macarena || 0844 Sala de Control NBI 6851 ||
|-
| Martín Diaz, Fernando || 0920 Sala de Control NBI 6851 || 363860
|-
| Martinez Fernandez, Jose || 6646 Sala de Control ECRH 6828 || 362785
|-
| Bueno Jañez, Luis Alberto || 6285 ||
|-
| Miguel Honrubia, Francisco J. || 6762 ||
|-
| Navarro Santana Miguel || 6824 ||
|-
| Pereira Gonzalez, Augusto || 0929 ||
|-
| Pons Villalonga, Pedro || 7926 || 363005
|-
| Portas Ferreiro, Ana Belén || 0929 ||
|-
| Ros Vivancos, Alfonso || 6642 Sala de Control ECRH 6828 Lab. μOndas 6808 || 362782
|-
| Sánchez Sarabia, Emilio || 6762 ||
|-
| Sebastián Alfaro, José Antonio || 6684 Sala de Control NBI 6851 || 362828
|-
| Tabarés Vazquez, Francisco Luis || 6458 ||
|-
| Tafalla García, David || 0843 ||
|-
| Tolkachev, Alexander || 6828 ||
|}

=== Fusion Theory Unit ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Calvo Rubio, Iván, Head Investigator || 6739 || 362872
|-
| Escoto López, Francisco Javier || || 363002
|-
| García Regaña, José Manuel || 7850 || 362938
|-
| Godino Sedano, Guillermo Luis || 7920 || 362780
|-
| González Jerez, Antonio || 7916 || 363000
|-
| López Bruna, Daniel || 6638 ||
|-
| [[User:Esolano|Solano (Rodríguez-Solano Ribeiro), Emilia R.]]|| 6153 || 362254
|-
| Sánchez González, Edilberto || 6162 || 362264
|-
| Thienpondt, Hanne || 2538 || 362037
|-
| Velasco Garasa, José Luis || 6504 || 363504
|}

=== Engineering Unit ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Medrano Casanova, Mercedes, Head Investigator || 6639 ||
|-
| Cabrera Pérez, Santiago || || 362994
|-
| Carrasco García, Ricardo || 7928 ||
|-
| Fernández Navarro, Alejandro || 6637 || 362771
|-
| Jimenez Denche, Andrés Enrique || 6584 ||
|-
| Kirpitchev, Igor || 6337 ||
|-
| Lapayese Puebla, Fernando || 0928 ||
|-
| Méndez Montero, Purificación || 6337 ||
|-
| de la Peña Gómez, Ángel || 6644 ||
|-
| Queral Mas, Vicente || 6419 || 362518
|-
| Ramos Rivero, Francisco || 6584 ||
|-
| Rincón Rincón, María Esther || 6637 ||
|-
| Soleto Palomo, M. Alfonso || 6636 ||
|-
| Weber Suárez, Moisés || 6636 ||
|}

=== Technology Division ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Rapisarda Socorro, David, Head Investigator || 0913/6335 (prov) || 362998
|-
| Brañas Lasala, Beatriz || 6289 ||
|-
| [[User:Elisabetta|Carella , Elisabetta]] || 6507 || 362253
|-
| D'Ovidio, Gianluca || 6419 || 362429
|-
| Fernández Berceruelo, Iván || 2579 ||
|-
| García Gonzalez, Juan Manuel || 7842 ||
|-
| Garcinuño Pindado, Belit || 6584 || 362717
|-
| Gonzalez Viada, María || 2582 || 362073
|-
| Gutierrez Pérez, Víctor || 6307 || 362413
|-
| Hernandez Diaz, Mª. Teresa || 2581 || 362071
|-
| Herranz Marco, Jesús Antonio || 0848 ||
|-
| Jimenez Baena, Francisco M. || 6204 ||
|-
| Jiménez Rey, David || 6640 ||
|-
| Malo Huerta, Marta || 6636 || 362769
|-
| Martín Laso, Montserrat || 6512 ||
|-
| Molla Lorente, Joaquín || 6397 || 362496
|-
| de la Morena Álvarez-Palencia, Cristina || 2600 ||
|-
| Moroño Guadalajara, Alejandro A. || 6372 ||
|-
| Mota García, Fernando || 6578 || 362708
|-
| Navas, Julia || || 362428
|-
| Ortíz, Christophe || 2582 || 362074
|-
| Ortiz Gandía, Maribel || 2582 || 362075
|-
| Palermo, Iole || 6784 ||
|-
| Patiño, Julian || || 362428
|-
| Regidor Serrano, David || 6584 ||
|-
| Roca Urgorri, Fernando || 6378 || 362480
|-
| Roldán Blanco, Marcelo || 2581 FIB-SEM 6790 || 362709
|-
| Román Chacón, Raquel || 6203 ||
|-
| Sánchez Sanz, Fernando José || 2581 FIB-SEM 6790 ||362702
|-
| Serrador Toledano, Laura || 2574 FIB-SEM 6790 ||
|-
| Valle Paisan, Francisco J. || 6204 ||
|-
| Vila Vazquez, Rafael Alberto || 6580 ||
|-
| Villamayor Callejo, Víctor || 6578 ||
|-
|}

=== Support Unit ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Ríos Márquez, Luis || ||
|-
| Barrera Orte, Laura || || 362262
|-
| Fernandez-Mayoralas López, Lorena || 6663 ||
|-
| Moreno García, Sabina || 6159 ||
|-
| Sánchez Rubio, Cristina || 6738 ||
|-
| Guerard Ortego, Carlos Kjell || - ||
|-

|}

LNF:Organization

2023-01-30T12:41:52Z

Jlvelasco: /* Laboratorio Nacional de Fusión */

== Laboratorio Nacional de Fusión ==

Asociación [[Euratom]]-[[CIEMAT]]: see [[Laboratorio Nacional de Fusión]].

Contact information is also available via the [http://www.ciemat.es/cargarFichaOrganizacion.do?idOrganizacion=F00 CIEMAT website]

The telephone numbers listed below are extensions; to call from outside the laboratory, dial: +34-91346xxxx, where xxxx is the extension. (When using 4-digit dialing from inside the laboratory: substitute any initial "0" by a "7".)

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Hidalgo Vera, Carlos, Director || 6498 ||
|-
| Guerard Ortego, Carlos Kjell || - ||
|-
|}

=== TJ-II Experimental Division ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Alonso de Pablo, Arturo || +49 3834 88 2342 ||
|-
| Baciero Adrados, Alfonso || 6493 || 362601
|-
| Blanco Villareal, Emilio J. || 7904 ||
|-
| de la Cal Heusch, Eduardo || 6317 ||
|-
| Carralero Ortiz, Daniel || 7852 ||
|-
| Castro Rojo, Rodrigo || 6419 ||
|-
| Estrada García, Mª. Teresa || 0845 ||
|-
| Fontdecaba Climent, Jose María || 6642 ||
|-
| García Cortés, Mª. Isabel || 6515 || 362625
|-
| Hernanz Hernanz, Francisco J. || 6641 ||
|-
| López Miranda, Belén || || 362093
|-
| McCarthy, Kieran Joseph || 0846 || 362934
|-
| Medina Yela, Francisco || 0847 || 362935
|-
| Ochando Garcia, Mª. Antonia || 6462 ||
|-
| de Pablos Hernández, Jose Luis || 6374 ||
|-
| Panadero Álvarez, Nerea || 6642 || 362781
|-
| Pastor Díaz, Ignacio || 6324 ||
|-
| Pastor Santos, Carmen || || 362564
|-
| Rattá Gutiérrez, Giuseppe A. || 7917 ||
|-
| Rodríguez Fernández, Mª. Carmen || 2611 ||
|-
| [[User:Admin|van Milligen, Boudewijn]] || 6379 || 362482
|-
| Vega Sánchez, Jesús Antonio || 6474 ||
|}

=== TJ-II Operation Division===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Ascasíbar, Enrique, Head Investigator || 6369 ||
|-
| Alegre Castro, Daniel || 0914 ||
|-
| Cappa Ascasíbar, Alvaro || 6646 Sala de Control ECRH 6828 ||
|-
| Cebrián Ruiz, Luis A. || 6338 ||
|-
| Chamorro Lastra, Manuel || 6641 ||
|-
| García Gomez, Raúl || 6641 ||
|-
| Guasp Pérez, Jose || 6510 ||
|-
| Guisse Arévalo, Víctor H. || 6285 ||
|-
| Liniers Vazquez, Macarena || 0844 Sala de Control NBI 6851 ||
|-
| Martín Diaz, Fernando || 0920 Sala de Control NBI 6851 ||
|-
| Martinez Fernandez, Jose || 6646 Sala de Control ECRH 6828 ||
|-
| Bueno Jañez, Luis Alberto || 6285 ||
|-
| Miguel Honrubia, Francisco J. || 6762 ||
|-
| Navarro Santana Miguel || 6824 ||
|-
| Pereira Gonzalez, Augusto || 0929 ||
|-
| Portas Ferreiro, Ana Belén || 0929 ||
|-
| Ros Vivancos, Alfonso || 6642 Sala de Control ECRH 6828 Lab. μOndas 6808 || 362782
|-
| Sánchez Sarabia, Emilio || 6762 ||
|-
| Sebastian Alfaro, José Antonio || 6684 Sala de Control NBI 6851 ||
|-
| Tabarés Vazquez, Francisco Luis || 6458 ||
|-
| Tafalla García, David || 0843 ||
|-
| Tolkachev, Alexander || 6828 ||
|}

=== Fusion Theory Unit ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Calvo Rubio, Iván, Head Investigator || 6739 || 362872
|-
| Escoto López, Francisco Javier || ||
|-
| García Regaña, José Manuel || 7850 ||
|-
| Godino Sedano, Guillermo Luis || ||
|-
| González Jerez, Antonio || 7916 ||
|-
| López Bruna, Daniel || 6638 ||
|-
| [[User:Esolano|Solano (Rodríguez-Solano Ribeiro), Emilia R.]]|| 6153 ||
|-
| Sánchez González, Edilberto || 6162 ||
|-
| Thienpondt, Hanne || ||
|-
| Velasco Garasa, José Luis || 6504 || 362610
|}

=== Engineering Unit ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Alonso, José Javier, Head Investigator || 6639 ||
|-
| Cabrera Pérez, Santiago || || 362994
|-
| Carrasco García, Ricardo || 7928 ||
|-
| Jimenez Denche, Andrés Enrique || 6584 ||
|-
| Kirpitchev, Igor || 6337 ||
|-
| Lapayese Puebla, Fernando || 0928 ||
|-
| Medrano Casanova, Mercedes || 6639 ||
|-
| Méndez Montero, Purificación || 6337 ||
|-
| de la Peña Gómez, Ángel || 6644 ||
|-
| Queral Mas, Vicente || 6419 || 362518
|-
| Ramos Rivero, Francisco || 6584 ||
|-
| Rincón Rincón, María Esther || 6637 ||
|-
| Soleto Palomo, M. Alfonso || 6636 ||
|-
| Weber Suárez, Moisés || 6636 ||
|}

=== Technology Division ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Rapisarda Socorro, David, Head Investigator || 0913/6335 (prov) || 362998
|-
| Brañas Lasala, Beatriz || 6289 ||
|-
| Carella, Elisabetta || 2579 ||
|-
| Fernández Berceruelo, Iván || 2579 ||
|-
| García Gonzalez, Juan Manuel || 7842 ||
|-
| Gonzalez Viada, María || 2582 ||
|-
| Hernandez Diaz, Mª. Teresa || 2581 ||
|-
| Herranz Marco, Jesús Antonio || 0848 ||
|-
| Jimenez Baena, Francisco M. || 6204 ||
|-
| Jiménez Rey, David || 6640 ||
|-
| Malo Huerta, Marta || 6204 ||
|-
| Martín Laso, Montserrat || 6512 ||
|-
| Molla Lorente, Joaquín || 6580 ||
|-
| de la Morena Álvarez-Palencia, Cristina || 2600 ||
|-
| Moroño Guadalajara, Alejandro A. || 6372 ||
|-
| Mota García, Fernando || 6578 ||
|-
| Ortíz, Christophe || 2582 ||
|-
| Palermo, Iole || 6784 ||
|-
| Regidor Serrano, David || 6584 ||
|-
| Roldán Blanco, Marcelo || 2574 Lab. 6512 ||
|-
| Román Chacón, Raquel || 6203 ||
|-
| Sánchez Sanz, Fernando José || 6578 FIB-SEM 6790 ||
|-
| Valle Paisan, Francisco J. || 6204 ||
|-
| Vila Vazquez, Rafael Alberto || 6580 ||
|-
| Villamayor Callejo, Víctor || 6578 ||
|-
|}

=== Support Unit ===

{|class="wikitable" style="vertical-align:top;"||
|-
!Name!!Telephone (old)!!IP-phone
|-
| Barrera Orte, Laura || || 362262
|-
| Fernandez-Mayoralas López, Lorena || 6663 ||
|-
| Moreno García, Sabina || 6159 ||
|-
| Sánchez Rubio, Cristina || 6738 ||
|}

LNF:Organization

2019-07-10T18:47:59Z

Jlvelasco: /* Laboratorio Nacional de Fusión */

== Laboratorio Nacional de Fusión ==

Asociación [[Euratom]]-[[CIEMAT]]: see [[Laboratorio Nacional de Fusión]].

Contact information is also available via the [http://www.ciemat.es/cargarFichaOrganizacion.do?idOrganizacion=F00 CIEMAT website]

The telephone numbers listed below are extensions; to call from outside the laboratory, dial: +34-91346xxxx, where xxxx is the extension. (When using 4-digit dialing from inside the laboratory: substitute any initial "0" by a "7".)

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Sánchez Sanz, Joaquin, Director || 6387
|-
| Moreno Garcia, Sabina || 6159
|-
| Guerard Ortego, Carlos Kjell || -
|-
|}

=== TJ-II Experimental Division ===

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Hidalgo Vera, Carlos, Head Investigator || 6498
|-
| Alonso de Pablo, Arturo || +49 3834 88 2342
|-
| Baciero Adrados, Alfonso || 0848
|-
| || 0917
|-
| Blanco Villareal, Emilio J. || 7904
|-
| de la Cal Heusch, Eduardo || 6317
|-
| Carralero Ortiz, Daniel || 7852
|-
| Castro Rojo, Rodrigo || 6419
|-
| Estrada García, Mª. Teresa || 0845
|-
| Fontdecaba Climent, Jose María || 6642
|-
| García Cortés, Mª. Isabel || 6515
|-
| Hernanz Hernanz, Francisco J. || 6641
|-
| Jiménez Rey, David || 6578
|-
| Losada Rodríguez, Ulises || 7918
|-
| McCarthy, Kieran Joseph || 0846
|-
| Medina Yela, Francisco || 0847
|-
| Ochando Garcia, Mª. Antonia || 6462
|-
| de Pablos Hernández, Jose Luis || 6374
|-
| Pastor Díaz, Ignacio || 6324
|-
| Pereira Gonzalez, Augusto || 0929
|-
| Rodríguez Fernández, Mª. Carmen || 2611
|-
| [[User:Admin|van Milligen, Boudewijn]] || 6379
|-
| Vega Sánchez, Jesús Antonio || 6474
|-
| Zurro Hernández, Bernardo || 6457
|}

=== TJ-II Operation Division===

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Ascasíbar, Enrique, Head Investigator || 6369
|-
| Alegre Castro, Daniel || 0914
|-
| Cappa Ascasíbar, Alvaro || 6646
|-
| Catalán Moreno, Gregorio || 6643
|-
| Chamorro Lastra, Manuel || 6641
|-
| García Gomez, Raúl || 6641
|-
| Guasp Pérez, Jose || 6510
|-
| Liniers Vazquez, Macarena || 0844
|-
| Martín Diaz, Fernando || 0920
|-
| Martinez Fernandez, Jose || 6646
|-
| Bueno Jañez, Luis Alberto || 6285
|-
| Miguel Honrubia, Francisco J. || 6762
|-
| Navarro Santana Miguel || 6824
|-
| Portas Ferreiro, Ana Belén || 0929
|-
| Rattá Gutiérrez, Giuseppe A. || 7917
|-
| Rojo Lozano, Beatriz || 0916
|-
| Ros Vivancos, Alfonso || 6642 || Sala Control 6828; || Lab. μOndas 6808
|-
| Sánchez Sarabia, Emilio || 6762
|-
| Sebastian Alfaro, José Antonio || 6684
|-
| Tabarés Vazquez, Francisco Luis || 6458
|-
| Tafalla García, David || 0843
|-
| Tolkachev, Alexander || 6828
|-
| Velasco de la Cuadra, Gregorio || 6819
|-
| Sala operación NBI || 6851
|}

=== Fusion theory Unit ===

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Calvo Rubio, Iván, Head Investigator || 6739
|-
| García Regaña, José Manuel || 6434
|-
| González Jerez, Antonio || 7916
|-
| López Bruna, Daniel || 6638
|-
| López Fraguas, Antonio || 0850
|-
| [[User:Esolano|Solano (Rodríguez-Solano Ribeiro), Emilia R.]]|| 6153
|-
| Sánchez González, Edilberto || 6162
|-
| Velasco Garasa, José Luis || 6504
|}

=== Engineering Unit ===

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Alonso, José Javier, Head Investigator || 6639
|-
| Botija Pérez, José || 6329
|-
| Carrasco García, Ricardo || 7928
|-
| Jimenez Denche, Andrés Enrique || 6584
|-
| Kirpitchev, Igor || 6337
|-
| Lapayese Puebla, Fernando || 0928
|-
| Medrano Casanova, Mercedes || 6639
|-
| Méndez Montero, Purificación || 6337
|-
| de la Peña Gómez, Ángel || 6644
|-
| Queral Mas, Vicente || 6419
|-
| Ramos Rivero, Francisco || 6584
|-
| Rincón Rincón, María Esther || 6637
|-
| Soleto Palomo, M. Alfonso || 6636
|-
| Weber Suárez, Moisés || 6636
|}

=== Technology Division ===

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Ibarra Sánchez, Ángel, Head Investigator || 6507
|-
| Arroyo Macias, José Manuel || 6636
|-
| Brañas Lasala, Beatriz || 6289
|-
| Carella, Elisabetta || 2579
|-
| Cruz Malagón, Darío Andrés || 2574 || Lab. 7842
|-
| Fernández Berceruelo, Iván || 2579
|-
| Fernández Paredes, Mª. Pilar || 2581
|-
| García Gonzalez, Juan Manuel || 7842
|-
| García Sanz, Ángela || 6335
|-
| Gonzalez Viada, María || 2582
|-
| Hernandez Diaz, Mª. Teresa || 2581
|-
| Herranz Marco, Jesús Antonio || 0848
|-
| Jimenez Baena, Francisco M. || 6204
|-
| Jiménez Piñero, Fernando || 2574
|-
| Malo Huerta, Marta || 6204
|-
| Martín Laso, Montserrat || 6512
|-
| Martín Martinez, Mª. Piedad || 2581
|-
| Molla Lorente, Joaquín || 6580
|-
| de la Morena Álvarez-Palencia, Cristina || 2600
|-
| Moroño Guadalajara, Alejandro A. || 6372
|-
| Mota García, Fernando || 6578
|-
| Ortíz, Christophe || 2582
|-
| Palermo, Iole || 6784
|-
| Rapisarda Socorro, David || 0913
|-
| Regidor Serrano, David || 6584
|-
| Rodríguez Salvador, Diego || 6613
|-
| Roldán Blanco, Marcelo || 2574 || Lab. 6512
|-
| Román Chacón, Raquel || 6203
|-
| Saavedra Aguera, Rafael || 2574 || Lab. Óptica 6578
|-
| Sánchez Sanz, Fernando José || 6578 || FIB-SEM 6790
|-
| Valle Paisan, Francisco J. || 6204
|-
| Vila Vazquez, Rafael Alberto || 6580
|-
| Villamayor Callejo, Víctor || 6578
|-
|}

=== Support Unit ===

{|
|-
!width="250" align="left"|Name!!width="50" align="left"|Telephone
|-
| Dabbah Ainstein, Dina || 7851
|-
| Moreno García, Sabina || 6159
|-
| Fernandez-Mayoralas López, Lorena || 6663
|-
| Sánchez Rubio, Cristina || 6738
|}

Stellarator optimization

2019-05-07T07:13:56Z

Jlvelasco:

In [[tokamak]]s, a significant part of the confining magnetic field is produced by the currents flowing in the plasma itself.
In contrast, the confining magnetic field of [[stellarator]]s may be dominated by externally imposed magnetic fields (depending on the configuration).
Since the confinement properties of toroidally confined devices depend sensitively on the magnetic field, the question arises whether this external control may be used to improve confinement properties, and thus facilitate the development of an economically attractive [[stellarator reactor]].

Several optimization strategies have been developed and/or are being studied.
<ref>H.E. Mynick, ''Transport optimization in stellarators'', [[doi:10.1063/1.2177643|Phys. Plasmas '''13''' (2006) 058102]]</ref>
* Optimization of [[Neoclassical transport]].<ref>H. Wobig, ''The theoretical basis of a drift-optimized stellarator reactor'', [[doi:10.1088/0741-3335/35/8/001|Plasma Phys. Control. Fusion '''35''' (1993) 903]]</ref> See [[omnigeneity]] and [[quasisymmetry]].
* Optimization of [[Anomalous transport]].<ref>H.E. Mynick, N. Pomphrey, and P. Xanthopoulos, ''Optimizing Stellarators for Turbulent Transport'', [[doi:10.1103/PhysRevLett.105.095004|Phys. Rev. Lett. '''105''' (2010) 095004]]</ref>

== Optimized stellarators ==

* [[W7-X]] - Neoclassical optimization; under construction
* [http://www.hsx.wisc.edu/ HSX] - Quasihelical symmetry; operational
* [http://web.utk.edu/~qps/ QPS] - Quasipoloidal symmetry; cancelled
* [http://ncsx.pppl.gov/ NCSX] - Quasi-axisymmetry; cancelled

Also see: [http://web.ornl.gov/sci/fed/stelnews/pdf/PoP_proposal.pdf US Stellarator proof-of-principle program]

== References ==
<references />

Neoclassical transport

2018-05-22T13:25:18Z

Jlvelasco: /* Limitations */

The '''Neoclassical Transport Model''' is one of the pillars of the physics of magnetically confined plasmas.
<ref>F.L. Hinton and R.D. Hazeltine, [[doi:10.1103/RevModPhys.48.239|Rev. Mod. Phys. '''48''', 239 (1976)]]</ref>
<ref>P. Helander and D.J. Sigmar, ''Collisional Transport in Magnetized Plasmas'', Cambridge University Press (2001) ISBN 0521807980</ref>
It provides a model for the transport of particles, momentum, and heat due to Coulomb collisions in confined plasmas in complex magnetic geometries, assuming that the plasma is in a quiescent state.
Thus, transport due to fluctuations lies outside of the scope of the theory.
The difference between the Neoclassical and the Classical models lies in the incorporation of geometrical effects, which give rise to complex particle orbits and drifts that were ignored in the latter.

== Brief summary of the theory ==

The theory starts from the Kinetic Equation for the mean particle distribution function <math>f_\alpha(x,v,t)</math>:

:<math>
\frac{\partial f_\alpha}{\partial t} + v\cdot \nabla f_\alpha + F \frac{\partial f_\alpha}{\partial v} = C_\alpha(f) + S_\alpha
</math>

where <math>\alpha</math> indicates the particle species, <math>v</math> is the velocity,
<math>F</math> is a force (the [http://en.wikipedia.org/wiki/Lorentz_force Lorentz force], <math>F = q(E + v \times B)</math> acting on the particle), <math>S_\alpha</math> a source and <math>C_\alpha</math> the [[Collision operator|collision operator]].
If the chosen collision operator is the Fokker-Planck operator, the equation is called the [http://en.wikipedia.org/wiki/Fokker-planck Fokker-Planck Equation].
The derivation of this collision operator is highly non-trivial and requires making specific assumptions;
in particular it must be assumed that a single collision has a small random effect on the particle velocity,
and that the collisions are sufficiently frequent for the resulting particle trajectory to be described as a random walk.
The collision operator must also satisfy some obvious conservation laws (conservation of particles, momentum, and energy).

Once the collision operator is decided, the moments of the Kinetic Equation can be computed.
These fluid moments are:

:<math>
n = \int{f d^3v}
</math>

(particle density)

:<math>
n u = \int{v f d^3v}
</math>

(particle flux)

:<math>
P = \int{m v \cdot v f d^3v}
</math>

(stress tensor)

:<math>
Q = \int{\frac{m v^2}{2} v f d^3v}
</math>

(energy flux)

:<math>
P' = \int{m (v-u) \cdot (v-u) f d^3v}
</math>

(pressure tensor)

:<math>
q = \int{\frac{m (v-u)^2}{2} (v-u) f d^3v}
</math>

(heat flux)

As an example, the evolution equation of the first moment becomes:
:<math>
\frac{\partial n}{\partial t} + \nabla \cdot (n u) = S_n
</math>
Similar conservation-type equations can be written down for the higher moments.

The main goal of Neoclassical transport theory is to provide a closed set of equations for the time evolution of these moments, for each particle species. Since the determination of any moment requires knowledge of the next order moment, this requires truncating the set of moments (''closure'' of the set of equations).
<ref>T.J.M. Boyd and J.J. Sanderson, ''The physics of plasmas'', Cambridge University Press (2003) ISBN 0521459125</ref>

It is customary to make a number of additional assumptions to facilitate the analysis: e.g., small gyroradius, nested magnetic surfaces, large parallel transport, Maxwellian distribution functions, etc.
As a consequence of such assumptions, the equations can be restated to reflect the 'radial' transport (normal to the flux surfaces, and averaged over flux surfaces).
Thus, the magnetic geometry is incorporated at an essential level in the theory.

The theory takes account of all particle motion associated with toroidal geometry; specifically, ''∇ B'' and curvature drifts, and passing and trapped particles (banana orbits).
The theory is valid for all [[Collisionality|collisionality]] regimes, and includes effects due to resistivity and viscosity. An important prediction of the theory is the [[Bootstrap current|bootstrap current]].

== Predictive and interpretative modelling ==

The derived transport equations can be used in several ways.

In predictive modelling, the transport is computed on the basis of the magnetic geometry, the collision operator, sources, and boundary conditions. The predicted transport and the resulting profiles can then be compared to experimental data.

In interpretative modelling, experimentally measured profiles are used to infer the corresponding sources or transport coefficients.

== Achievements ==
Neoclassical models have been used with success to predict transport under certain specific conditions.
''(Citation needed)''
The [[Bootstrap current|bootstrap current]] and radial electric field predicted by the theory are confirmed experimentally, both qualitatively and quantitatively in most scenarios.
''(Citation needed)''
In experimental studies, Neoclassical transport estimates are often used as a "baseline" transport level -
even though experimental values often exceed Neoclassical estimates by an order of magnitude or more.
In any case, this "baseline" level facilitates the comparison between devices.
Neoclassical theory is also used in the process of machine design and optimisation.
<ref>M. Hirsch et al. ''Major results from the stellarator Wendelstein 7-AS'', [[doi:10.1088/0741-3335/50/5/053001|Plasma Phys. Control. Fusion '''50''', 5 (2008) 053001]]</ref>

== Limitations ==
Neoclassical theory is based on a set of assumptions that limit its range of applicability and explain why it is not capable of predicting transport in all magnetic confinement devices and under all circumstances.
These are:
* Maxwellianity. This assumption implies that a certain minimum level of [[Collisionality|collisionality]] is needed in order to ensure that Maxwellianisation is effective. The strong drives and resulting gradients that characterise fusion-grade plasmas often lead to a violation of this assumption.
* A fixed geometry. Neoclassical transport is calculated in a static magnetic geometry. In actual experiments (especially Tokamaks), the magnetic field evolves along with the plasma itself, leading to a modification of net transport. While a slow evolution (with respect to typical transport time scales) should not be problematic, rapid changes (such as magnetic reconnections) are outside of the scope of the theory.
* The linearity of the model. Neoclassical theory is a linear theory in which profiles are computed from sources, boundary conditions, and transport coefficients (that depend linearly on the profiles). No non-linear feedback of the profiles on the transport coefficients is not usually contemplated. However, there are many experimental studies that show that the profiles feed back non-linearly on transport (via [[TJ-II:Turbulence|turbulence]]), leading to some degree of [[Self-Organised Criticality|self-organisation]].
* Locality. Neoclassical theory is a theory of diffusion, and therefore it assumes that radial particle motion between collisions is small with respect to any other relevant spatial scales. This assumption then allows writing down differential equations, expressing the fluxes in terms of ''local'' gradients. This basic assumption is violated under specific conditions, which may include: (a) the low-collisionality limit, (b) any situation in which the gradient scale length is very small (e.g., [[Internal Transport Barrier]]s), (c) locations close to the plasma edge<ref>T. Fülöp, P. Helander, [[doi:10.1063/1.1372179|Phys. Plasmas 8, 3305 (2001)]]</ref><ref>V. Tribaldos and J. Guasp, ''Neoclassical global flux simulations in stellarators'', [[doi:10.1088/0741-3335/47/3/010|Plasma Phys. Control. Fusion '''47''' (2005) 545]]</ref>, and (d) particles transported in ''streamers''. Such phenomena could give rise to [[Non-diffusive transport|super-diffusion]]. Points (a) through (c) can be handled by using a Monte Carlo or Master Equation approach instead of deriving differential equations.
* Markovianity. A second assumption underlying diffusive models (including Neoclassics) is Markovianity, implying that the motion of any particle is only determined by its current velocity and position. However, there are situations, such as stochastic magnetic field regions, persistent turbulent eddies, or transport barriers, where this assumption may be violated (due to trapping effects, so that the preceding history of the particle trajectory becomes important). Typically, this would then give rise to [[Non-diffusive transport|sub-diffusion]].

== References ==
<references />

Neoclassical transport

2018-05-22T13:23:18Z

Jlvelasco:

The '''Neoclassical Transport Model''' is one of the pillars of the physics of magnetically confined plasmas.
<ref>F.L. Hinton and R.D. Hazeltine, [[doi:10.1103/RevModPhys.48.239|Rev. Mod. Phys. '''48''', 239 (1976)]]</ref>
<ref>P. Helander and D.J. Sigmar, ''Collisional Transport in Magnetized Plasmas'', Cambridge University Press (2001) ISBN 0521807980</ref>
It provides a model for the transport of particles, momentum, and heat due to Coulomb collisions in confined plasmas in complex magnetic geometries, assuming that the plasma is in a quiescent state.
Thus, transport due to fluctuations lies outside of the scope of the theory.
The difference between the Neoclassical and the Classical models lies in the incorporation of geometrical effects, which give rise to complex particle orbits and drifts that were ignored in the latter.

== Brief summary of the theory ==

The theory starts from the Kinetic Equation for the mean particle distribution function <math>f_\alpha(x,v,t)</math>:

:<math>
\frac{\partial f_\alpha}{\partial t} + v\cdot \nabla f_\alpha + F \frac{\partial f_\alpha}{\partial v} = C_\alpha(f) + S_\alpha
</math>

where <math>\alpha</math> indicates the particle species, <math>v</math> is the velocity,
<math>F</math> is a force (the [http://en.wikipedia.org/wiki/Lorentz_force Lorentz force], <math>F = q(E + v \times B)</math> acting on the particle), <math>S_\alpha</math> a source and <math>C_\alpha</math> the [[Collision operator|collision operator]].
If the chosen collision operator is the Fokker-Planck operator, the equation is called the [http://en.wikipedia.org/wiki/Fokker-planck Fokker-Planck Equation].
The derivation of this collision operator is highly non-trivial and requires making specific assumptions;
in particular it must be assumed that a single collision has a small random effect on the particle velocity,
and that the collisions are sufficiently frequent for the resulting particle trajectory to be described as a random walk.
The collision operator must also satisfy some obvious conservation laws (conservation of particles, momentum, and energy).

Once the collision operator is decided, the moments of the Kinetic Equation can be computed.
These fluid moments are:

:<math>
n = \int{f d^3v}
</math>

(particle density)

:<math>
n u = \int{v f d^3v}
</math>

(particle flux)

:<math>
P = \int{m v \cdot v f d^3v}
</math>

(stress tensor)

:<math>
Q = \int{\frac{m v^2}{2} v f d^3v}
</math>

(energy flux)

:<math>
P' = \int{m (v-u) \cdot (v-u) f d^3v}
</math>

(pressure tensor)

:<math>
q = \int{\frac{m (v-u)^2}{2} (v-u) f d^3v}
</math>

(heat flux)

As an example, the evolution equation of the first moment becomes:
:<math>
\frac{\partial n}{\partial t} + \nabla \cdot (n u) = S_n
</math>
Similar conservation-type equations can be written down for the higher moments.

The main goal of Neoclassical transport theory is to provide a closed set of equations for the time evolution of these moments, for each particle species. Since the determination of any moment requires knowledge of the next order moment, this requires truncating the set of moments (''closure'' of the set of equations).
<ref>T.J.M. Boyd and J.J. Sanderson, ''The physics of plasmas'', Cambridge University Press (2003) ISBN 0521459125</ref>

It is customary to make a number of additional assumptions to facilitate the analysis: e.g., small gyroradius, nested magnetic surfaces, large parallel transport, Maxwellian distribution functions, etc.
As a consequence of such assumptions, the equations can be restated to reflect the 'radial' transport (normal to the flux surfaces, and averaged over flux surfaces).
Thus, the magnetic geometry is incorporated at an essential level in the theory.

The theory takes account of all particle motion associated with toroidal geometry; specifically, ''∇ B'' and curvature drifts, and passing and trapped particles (banana orbits).
The theory is valid for all [[Collisionality|collisionality]] regimes, and includes effects due to resistivity and viscosity. An important prediction of the theory is the [[Bootstrap current|bootstrap current]].

== Predictive and interpretative modelling ==

The derived transport equations can be used in several ways.

In predictive modelling, the transport is computed on the basis of the magnetic geometry, the collision operator, sources, and boundary conditions. The predicted transport and the resulting profiles can then be compared to experimental data.

In interpretative modelling, experimentally measured profiles are used to infer the corresponding sources or transport coefficients.

== Achievements ==
Neoclassical models have been used with success to predict transport under certain specific conditions.
''(Citation needed)''
The [[Bootstrap current|bootstrap current]] and radial electric field predicted by the theory are confirmed experimentally, both qualitatively and quantitatively in most scenarios.
''(Citation needed)''
In experimental studies, Neoclassical transport estimates are often used as a "baseline" transport level -
even though experimental values often exceed Neoclassical estimates by an order of magnitude or more.
In any case, this "baseline" level facilitates the comparison between devices.
Neoclassical theory is also used in the process of machine design and optimisation.
<ref>M. Hirsch et al. ''Major results from the stellarator Wendelstein 7-AS'', [[doi:10.1088/0741-3335/50/5/053001|Plasma Phys. Control. Fusion '''50''', 5 (2008) 053001]]</ref>

== Limitations ==
Neoclassical theory is based on a set of assumptions that limit its range of applicability and explain why it is not capable of predicting transport in all magnetic confinement devices and under all circumstances.
These are:
* Maxwellianity. This assumption implies that a certain minimum level of [[Collisionality|collisionality]] is needed in order to ensure that Maxwellianisation is effective. The strong drives and resulting gradients that characterise fusion-grade plasmas often lead to a violation of this assumption.
* A fixed geometry. Neoclassical transport is calculated in a static magnetic geometry. In actual experiments (especially Tokamaks), the magnetic field evolves along with the plasma itself, leading to a modification of net transport. While a slow evolution (with respect to typical transport time scales) should not be problematic, rapid changes (such as magnetic reconnections) are outside of the scope of the theory.
* The linearity of the model. Neoclassical theory is a linear theory in which profiles are computed from sources, boundary conditions, and transport coefficients (that depend linearly on the profiles). No non-linear feedback of the profiles on the transport coefficients is contemplated. However, there are many experimental studies that show that the profiles feed back non-linearly on transport (via [[TJ-II:Turbulence|turbulence]]), leading to some degree of [[Self-Organised Criticality|self-organisation]].
* Locality. Neoclassical theory is a theory of diffusion, and therefore it assumes that particle motion between collisions is small with respect to any other relevant spatial scales. This assumption then allows writing down differential equations, expressing the fluxes in terms of ''local'' gradients. This basic assumption is violated under specific conditions, which may include: (a) the low-collisionality limit, (b) any situation in which the gradient scale length is very small (e.g., [[Internal Transport Barrier]]s), (c) locations close to the plasma edge<ref>T. Fülöp, P. Helander, [[doi:10.1063/1.1372179|Phys. Plasmas 8, 3305 (2001)]]</ref><ref>V. Tribaldos and J. Guasp, ''Neoclassical global flux simulations in stellarators'', [[doi:10.1088/0741-3335/47/3/010|Plasma Phys. Control. Fusion '''47''' (2005) 545]]</ref>, and (d) particles transported in ''streamers''. Such phenomena could give rise to [[Non-diffusive transport|super-diffusion]]. Points (a) through (c) can be handled by using a Monte Carlo or Master Equation approach instead of deriving differential equations.
* Markovianity. A second assumption underlying diffusive models (including Neoclassics) is Markovianity, implying that the motion of any particle is only determined by its current velocity and position. However, there are situations, such as stochastic magnetic field regions, persistent turbulent eddies, or transport barriers, where this assumption may be violated (due to trapping effects, so that the preceding history of the particle trajectory becomes important). Typically, this would then give rise to [[Non-diffusive transport|sub-diffusion]].

== References ==
<references />

TJ-II:Evaluation of Neoclassical transport correction terms in TJ-II

2018-03-09T10:27:55Z

Jlvelasco: Vuelto a corregir la referencia 2

== Experimental campaign ==
2018 Spring

== Proposal title ==
Evaluation of Neoclassical transport correction terms in TJ-II

== Name and affiliation of proponent ==
D. Carralero, J.L. Velasco, T. Estrada and the TJ-II team

== Details of contact person at LNF (if applicable) ==
email: daniel.carralero@ciemat.es

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==

'''Background'''

Neoclassical transport is widely considered to determine radial energy transport in high-temperature plasmas of stellarators up to a certain radial position <ref> A. Dinklage et al., ''Inter-machine validation study of neoclassical transport modelling in medium- to high-density stellarator-heliotron plasmas'', Nucl. Fusion, 53 (2013), 6. </ref>. In particular, for low-density ECH-heated stellarator plasmas, the levels of electron energy transport predicted by neoclassical simulations <ref> J. L. Velasco et al., ''Study of the neoclassical radial electric field of the TJ-II flexible heliac'', Plasma Physics and Controlled Fusion 56 (2012) 015005 </ref> are comparable to those estimated in the experiment, e.g. <ref name=Tallents> S. Tallents et al., ''Transport analysis in an electron cyclotron heating power scan of TJ-II plasmas'' 2014 Plasma Physics and Controlled Fusion 56 07502 </ref>, and the measured density and power dependence of the energy confinement time <ref> E. Ascasíbar et al., ''Magnetic configuration and plasma parameter dependence of the energy confinement time in ECR heated plasmas from the TJ-II stellarator'', Nucl. Fusion 45 (2005), 276 </ref> is in reasonable agreement with neoclassical predictions (assuming that the electrons are in the 1/nu transport regime). In this experiment, we would like to take a closer look to the parameter dependence of the energy flux and, in particular to the Er dependence.

Going beyond the plain comparison, for selected discharges, between the neoclassical predictions of radial fluxes and the experimental measurements is relevant for two reasons. For starters, it allows to identify and characterize possible systematic deviations. More interestingly, in a real plasma, the particles are not in a pure regime (e.g. the 1/nu, as mentioned above, sqrt(nu), plateau, etc), but in a mixture of regimes, since for a given temperature they are approximately distributed according to a Maxwellian. Studying the parameter dependence of the energy flux can allow to identify to what extent the different regimes contribute to transport in real conditions. This may something relevant, e.g. if, when optimizing a magnetic configuration with respect to neoclassical transport, reducing the transport level of one particular regime is incompatible with reducing that of other regimes. Currently, this kind of analysis is already under development in the W-7X optimized stellarator <ref> J. A. Alonso et al., ''Ion heat transport in low-density W7-X plasmas'', 44th EPS Conference on Plasma Physics, Belfast, Northern Ireland, June 26- 30, 2017 </ref>.

As for the Er dependence, it is worth noting that the contribution of the tangential magnetic drift (MTD) in the ion drift kinetic equation at low collisionalities has traditionally been considered negligible for high aspect ratio machines when the radial electric field is large. This assumption has recently been called into question for realistic values of Er, meaning that heat and particle fluxes calculated with NC transport coefficients derived without taking into account the MTD could be inaccurate. This would be specially the case when approaching the root transition, in which Er~0 and the role of MTD becomes particularly relevant. In this situation, conventional calculations predict a clear maximum on radial fluxes around Er=0, e.g. <ref> J. L. Velasco et al., ''Study of the neoclassical radial electric field of the TJ-II flexible heliac'', Plasma Physics and Controlled Fusion 56 (2012) 015005 </ref>, while the peak in ion transport obtained with simulations carried out taking MTD into account <ref> S. Matsuoka et al., ''Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas'', Physics of Plasmas 22 (2015), 072511 </ref> <ref> B. Huang et al., ''Benchmark of the local drift-kinetic models for neoclassical transport simulation in helical plasmas'', Physics of Plasmas 24 (2017), 022503 </ref> is reduced in amplitude and displaced towards Er < 0 (the peak in electron transport should appear then at Er>0). The difference between the two trends could be large enough to be clearly noticeable experimentally, thus representing a good method to evaluate the general validity of the NC transport predictions and the relevance of the MTD in a real-life plasma. It is important to notice that, while this effect should be noted within a wide range of collisionalities, this dependence on the Er does not appear at the plateau regime. Therefore, collisionality must be kept below the threshold for such regime.

With this purpose, we propose to characterize radial electron transport in ECH plasmas of the TJ-II stellarator by realizing density and power scans around the root transition. The objective of these scans would be to obtain a set of shots with comparable Te and ne gradients and different values of Er (comprising a wide range of 0 < Er and Er > 0 values) so that experimental qr,e (Er) can be determined and compared with the corresponding simulations with and without MTD.

'''Approach'''

In TJ-II, the radial electric field can be measured for a wide radial range by means of Doppler reflectometry (DR). Besides, although qr,e can’t be directly measured, in a stationary plasma, the divergence of qe is determined locally by source terms, which can be evaluated approximately based on data available in TJ-II: the most relevant source terms include radiation (which is considered to be small <ref name=Tallents />), ECH power deposition (which will be estimated at the beginning of the experimental day by means of fast modulation of one of the gyrotrons, and should also be small in the radial region probed by the DR) and energy transfer to the ion species, which can be calculated based on density and temperature profiles. In TJ-II, the root transition can be accessed either by a change in density or by a change in heating power. In particular, the Er measured by DR has been observed to change strongly with moderate increases of ne around a critical density determined by the injected heating power. These changes in the electric field seem to have a minor effect on ne and Te profiles, thus providing an scenario in which qr,e (Er) can be obtained experimentally for a range of roughly equivalent ne and Te gradients. This is important in order to allow for a meaningful comparison between measurements and theoretical predictions. Since the plateau regime is to be avoided, when selecting the combination of densities and heating powers for the experiments, collisionality must be minimized whenever possible (i.e., reducing density, or preferably, increasing Te). As well, freshly lithiated walls are required in order to minimize the role of radiation on the electron power balance.

'''Experiment description'''

First, the radial electric field will be measured on a series of standard configuration ECH plasmas with constant heating power and increasing densities around the root transition critical density. This scan should provide a set of discharges with constant Te profiles (ECH alignment adjustment may be required to ensure that) and changing ne profiles. The range of densities will be selected by adjusting the heating power value in order to allow the DR in the rho ~ [0.3-0.8] range. Some trade-off maybe necessary to ensure good TS profile data. Ti will be measured at the plasma core by the NPA. At least, 10 different Er profiles should be measured this way, with some intermediate radial region being covered by all density values.
Second, a fixed density value will be selected such that an equivalent scan can be carried out by small increments of PECH. In this scan, the radial region probed by the reflectometer remains constant, as density profiles can be made roughly constant, while Te profiles will change. The density must be such that good TS data is collected, the root transition takes place for a power roughly around that of a gyrotron at full power and DR probes the [0.3-0.8] range.
Finally, one of the previous scans could be repeated in a high ripple configuration in order to check the impact on the measurements of the increased transport.

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation:

10 Er profiles are required (in order to produce an empirical qe,r (Er) curve with reasonable resolution) for each scan. This means an absolute minimum of 20 discharges. Since fine tunning may required in ECH alignment and fueling in order to achieve constant profiles, two full days of operation will probably be required (one per scan). Ideally, both days would be separated in time in order to properly evaluate the results.

* Essential diagnostic systems:

The essential diagnostics are those used to measure Er (Doppler reflectometer) and Te and ne profiles (Thomson scattering, plus all other diagnostics involved in the Bayesian profile determination, such as interferometer, ECE, Helium beam, etc).

Ti measurements from the NPA will be useful to estimate the ion temperature profiles used for NC simulations and e-i energy exchange estimations. Bolometry will be used to monitor radiation losses.

* Type of plasmas (heating configuration):

Standard configuration (100_44_64) with ECH heating. For the high ripple scan, additional shots would be carried out in ECH heated plasmas in 100_32_60 configuration.

* Specific requirements on wall conditioning if any:

Fresh lithiation is required in order to minimize the effect of impurities in the radiation profile.

== Preferred dates and degree of flexibility ==
Preferred dates:

Any time from 01-05-2018 except:

- 22 to 24-05-2018

- 18 to 25-06-2018

== References ==
<references /> 

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Evaluation of Neoclassical transport correction terms in TJ-II

2018-03-09T10:26:49Z

Jlvelasco: He corregido la referencia 2

== Experimental campaign ==
2018 Spring

== Proposal title ==
Evaluation of Neoclassical transport correction terms in TJ-II

== Name and affiliation of proponent ==
D. Carralero, J.L. Velasco, T. Estrada and the TJ-II team

== Details of contact person at LNF (if applicable) ==
email: daniel.carralero@ciemat.es

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==

'''Background'''

Neoclassical transport is widely considered to determine radial energy transport in high-temperature plasmas of stellarators up to a certain radial position <ref> A. Dinklage et al., ''Inter-machine validation study of neoclassical transport modelling in medium- to high-density stellarator-heliotron plasmas'', Nucl. Fusion, 53 (2013), 6. </ref>. In particular, for low-density ECH-heated stellarator plasmas, the levels of electron energy transport predicted by neoclassical simulations <ref> J. L. Velasco et al., ''Study of the neoclassical radial electric field of the TJ-II flexible heliac'' Plasma Phys. Control. Fusion, 54 015005 </ref> are comparable to those estimated in the experiment, e.g. <ref name=Tallents> S. Tallents et al., ''Transport analysis in an electron cyclotron heating power scan of TJ-II plasmas'' 2014 Plasma Physics and Controlled Fusion 56 07502 </ref>, and the measured density and power dependence of the energy confinement time <ref> E. Ascasíbar et al., ''Magnetic configuration and plasma parameter dependence of the energy confinement time in ECR heated plasmas from the TJ-II stellarator'', Nucl. Fusion 45 (2005), 276 </ref> is in reasonable agreement with neoclassical predictions (assuming that the electrons are in the 1/nu transport regime). In this experiment, we would like to take a closer look to the parameter dependence of the energy flux and, in particular to the Er dependence.

Going beyond the plain comparison, for selected discharges, between the neoclassical predictions of radial fluxes and the experimental measurements is relevant for two reasons. For starters, it allows to identify and characterize possible systematic deviations. More interestingly, in a real plasma, the particles are not in a pure regime (e.g. the 1/nu, as mentioned above, sqrt(nu), plateau, etc), but in a mixture of regimes, since for a given temperature they are approximately distributed according to a Maxwellian. Studying the parameter dependence of the energy flux can allow to identify to what extent the different regimes contribute to transport in real conditions. This may something relevant, e.g. if, when optimizing a magnetic configuration with respect to neoclassical transport, reducing the transport level of one particular regime is incompatible with reducing that of other regimes. Currently, this kind of analysis is already under development in the W-7X optimized stellarator <ref> J. A. Alonso et al., ''Ion heat transport in low-density W7-X plasmas'', 44th EPS Conference on Plasma Physics, Belfast, Northern Ireland, June 26- 30, 2017 </ref>.

As for the Er dependence, it is worth noting that the contribution of the tangential magnetic drift (MTD) in the ion drift kinetic equation at low collisionalities has traditionally been considered negligible for high aspect ratio machines when the radial electric field is large. This assumption has recently been called into question for realistic values of Er, meaning that heat and particle fluxes calculated with NC transport coefficients derived without taking into account the MTD could be inaccurate. This would be specially the case when approaching the root transition, in which Er~0 and the role of MTD becomes particularly relevant. In this situation, conventional calculations predict a clear maximum on radial fluxes around Er=0, e.g. <ref> J. L. Velasco et al., ''Study of the neoclassical radial electric field of the TJ-II flexible heliac'', Plasma Physics and Controlled Fusion 56 (2012) 015005 </ref>, while the peak in ion transport obtained with simulations carried out taking MTD into account <ref> S. Matsuoka et al., ''Effects of magnetic drift tangential to magnetic surfaces on neoclassical transport in non-axisymmetric plasmas'', Physics of Plasmas 22 (2015), 072511 </ref> <ref> B. Huang et al., ''Benchmark of the local drift-kinetic models for neoclassical transport simulation in helical plasmas'', Physics of Plasmas 24 (2017), 022503 </ref> is reduced in amplitude and displaced towards Er < 0 (the peak in electron transport should appear then at Er>0). The difference between the two trends could be large enough to be clearly noticeable experimentally, thus representing a good method to evaluate the general validity of the NC transport predictions and the relevance of the MTD in a real-life plasma. It is important to notice that, while this effect should be noted within a wide range of collisionalities, this dependence on the Er does not appear at the plateau regime. Therefore, collisionality must be kept below the threshold for such regime.

With this purpose, we propose to characterize radial electron transport in ECH plasmas of the TJ-II stellarator by realizing density and power scans around the root transition. The objective of these scans would be to obtain a set of shots with comparable Te and ne gradients and different values of Er (comprising a wide range of 0 < Er and Er > 0 values) so that experimental qr,e (Er) can be determined and compared with the corresponding simulations with and without MTD.

'''Approach'''

In TJ-II, the radial electric field can be measured for a wide radial range by means of Doppler reflectometry (DR). Besides, although qr,e can’t be directly measured, in a stationary plasma, the divergence of qe is determined locally by source terms, which can be evaluated approximately based on data available in TJ-II: the most relevant source terms include radiation (which is considered to be small <ref name=Tallents />), ECH power deposition (which will be estimated at the beginning of the experimental day by means of fast modulation of one of the gyrotrons, and should also be small in the radial region probed by the DR) and energy transfer to the ion species, which can be calculated based on density and temperature profiles. In TJ-II, the root transition can be accessed either by a change in density or by a change in heating power. In particular, the Er measured by DR has been observed to change strongly with moderate increases of ne around a critical density determined by the injected heating power. These changes in the electric field seem to have a minor effect on ne and Te profiles, thus providing an scenario in which qr,e (Er) can be obtained experimentally for a range of roughly equivalent ne and Te gradients. This is important in order to allow for a meaningful comparison between measurements and theoretical predictions. Since the plateau regime is to be avoided, when selecting the combination of densities and heating powers for the experiments, collisionality must be minimized whenever possible (i.e., reducing density, or preferably, increasing Te). As well, freshly lithiated walls are required in order to minimize the role of radiation on the electron power balance.

'''Experiment description'''

First, the radial electric field will be measured on a series of standard configuration ECH plasmas with constant heating power and increasing densities around the root transition critical density. This scan should provide a set of discharges with constant Te profiles (ECH alignment adjustment may be required to ensure that) and changing ne profiles. The range of densities will be selected by adjusting the heating power value in order to allow the DR in the rho ~ [0.3-0.8] range. Some trade-off maybe necessary to ensure good TS profile data. Ti will be measured at the plasma core by the NPA. At least, 10 different Er profiles should be measured this way, with some intermediate radial region being covered by all density values.
Second, a fixed density value will be selected such that an equivalent scan can be carried out by small increments of PECH. In this scan, the radial region probed by the reflectometer remains constant, as density profiles can be made roughly constant, while Te profiles will change. The density must be such that good TS data is collected, the root transition takes place for a power roughly around that of a gyrotron at full power and DR probes the [0.3-0.8] range.
Finally, one of the previous scans could be repeated in a high ripple configuration in order to check the impact on the measurements of the increased transport.

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation:

10 Er profiles are required (in order to produce an empirical qe,r (Er) curve with reasonable resolution) for each scan. This means an absolute minimum of 20 discharges. Since fine tunning may required in ECH alignment and fueling in order to achieve constant profiles, two full days of operation will probably be required (one per scan). Ideally, both days would be separated in time in order to properly evaluate the results.

* Essential diagnostic systems:

The essential diagnostics are those used to measure Er (Doppler reflectometer) and Te and ne profiles (Thomson scattering, plus all other diagnostics involved in the Bayesian profile determination, such as interferometer, ECE, Helium beam, etc).

Ti measurements from the NPA will be useful to estimate the ion temperature profiles used for NC simulations and e-i energy exchange estimations. Bolometry will be used to monitor radiation losses.

* Type of plasmas (heating configuration):

Standard configuration (100_44_64) with ECH heating. For the high ripple scan, additional shots would be carried out in ECH heated plasmas in 100_32_60 configuration.

* Specific requirements on wall conditioning if any:

Fresh lithiation is required in order to minimize the effect of impurities in the radiation profile.

== Preferred dates and degree of flexibility ==
Preferred dates:

Any time from 01-05-2018 except:

- 22 to 24-05-2018

- 18 to 25-06-2018

== References ==
<references /> 

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Validation of bootstrap predictions

2018-02-14T10:55:30Z

Jlvelasco: /* Preferred dates and degree of flexibility */

== Experimental campaign ==
2018 Spring

== Proposal title ==
''Validation of bootstrap predictions''.

== Name and affiliation of proponent ==
José Luis Velasco, Kieran McCarthy, Enrique Ascasíbar, Shinsuke Satake (NIFS) ''et al''.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

The bootstrap current is a neoclassical effect triggered by the radial gradients of the density and temperature in the presence of an inhomogeneous magnetic field. This current may perturb the desired magnetic configuration produced by the external coils, which is especially problematic for shearless devices, such as W7-X or TJ-II. Therefore, in order to design magnetic configurations and suitable operation scenarios, it is necessary to gain confidence on the available neoclassical predictions of bootstrap current (see e.g. <ref>Velasco 2011 PPCF</ref> and references therein). While the ion parallel flow (the ion contribution to the bootstrap current) is considered to be validated, see e.g. <ref>Arevalo 2013 NF</ref>, the electron contribution is not. Since no measurement of the electron parallel flow is available, what is left is to measure the total current or its effect on the magnetic configuration <ref>Colchin 1990 PoF, Watanabe 1995 NF, Estrada 2002 PPCF, Schmitt 2015 PoP</ref>. The proponents have participated in a recent experiment in the deuterium campaign of LHD <ref>Satake 2017 ISHW</ref>.

'''Objectives.'''

In this experiment we will create ECH plasmas with constant line-density and electron temperature during all the discharge. The working gas will be alternatively Hydrogen and Helium, and we will scan (shot-to-shot) the radial position of ECH absortion. We will measure the time evolution of the current with the Rogowski coils and two components of the magnetic field with the Motional Stark Effect diagnostic <ref>McCarthy 2015 CPP</ref>at the end of the discharge (measurements of the vacuum field will also be necessary). We will then compare the measurements with neoclassical simulations.

Off-axis heating should lead to lower electron temperatures, and use of Helium to larger effective charge. Both things should contribute to a faster equilibration of the total current and thus make the measurements easier. We will consider adding short gas puffs of impurities (e.g. N) in order to further accelerate the time evolution of the current.

== If applicable, International or National funding project or entity ==
EUROfusion WP18.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 2 day (1 H, 1 He)
* Essential diagnostic systems:

We will measure:

- The time evolution of the total current <math><I_t(t)></math> with the Rogowsky coils.

- Two components of the magnetic field at the end of the discharge (when <math><I_t(t)></math> has converged) with the Motional Stark Effect

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS) and the He beam.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density and electron temperature as measured by ECE. We will scan the position of one of the gyrotrons in order to change the electron temperature profile.
* Specific requirements on wall conditioning if any: Lithium coating if considered necessary for stable plasmas
* External users: need a local computer account for data access: no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): J. L. Velasco and K. J. McCarthy will be unavailable from 10th to 12th of April (CWGM). K. J. McCarthy will be unavailable from 23rd to 27th of April (W7-X) and on Thursday 17th of May (Erasmus Laboratories).

== References ==
<references />

See also

http://fusionsites.ciemat.es/jlvelasco/files/notes/ICasal_informe.pdf

and

http://fusionsites.ciemat.es/jlvelasco/files/presentations/velasco_etal_bootstrap.pdf

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Experimental proposals

2018-02-12T19:37:37Z

Jlvelasco: /* Experimental proposals, 2018 Spring */

[[File:TJII_model.jpg|400px|thumb|right|TJ-II Model]]

== Creation of a new proposal ==

# Log in to the FusionWiki. If you don't have an account, request one by clicking 'Create account' in the left-hand menu.
# ''Type the name of your proposal page in the field below''. The required format is: 'TJ-II:Title of my proposal'. Note the 'TJ-II:' at the beginning!
# Click 'Create new proposal'. Your proposal page will be created. Edit and save (please use 'Show preview' before saving the final version).

<inputbox>
type=create
default=TJ-II:Title of my proposal
buttonlabel=Create new proposal with this title
preload=TJ-II:Proposal_template
</inputbox>

The proposal page is created on the basis of this [[TJ-II:Proposal template|Proposal template]]. You do not need to view or modify it.

== Inclusion of your proposal in the proposal list ==

* Edit the table below and add your proposal (instructions in the table). The link to your proposal is as follows: <nowiki>[[TJ-II:Title of my proposal|]]</nowiki> (the final character before the closing brackets <nowiki>]]</nowiki> is a vertical slash).

== Experimental proposals, 2018 Spring==
Deadline: March 7, 2018

{| class="wikitable sortable" width="100%" border="1" cellpadding="5" cellspacing="0" style="text-align:left"
|- style="background:#FFDEAD;"
! width="10%"| '''Nr.'''
! width="60%"| '''Title'''
! width="30%"| '''Proponent(s)'''




|-
 | 1
 | [[TJ-II:Observation of suprathermal ions with Neutral Particle Analyzers during electron cyclotron heating in the TJ-II stellarator|Observation of suprathermal ions with Neutral Particle Analyzers during electron cyclotron heating in the TJ-II stellarator]]
 | [mailto:josepmaria.fontdecaba@ciemat.es J.M. Fontdecaba]



|-
 | 2
 | [[TJ-II:Poloidal 2D scans to investigate potential and density profiles in the TJ-II stellarator using dual Heavy ion beam probe diagnostic|Poloidal 2D scans to investigate potential and density profiles in the TJ-II stellarator using dual Heavy ion beam probe diagnostic]]
 | [mailto:ridhimas757@gmail.com R. Sharma]

|-
 | 3
 | [[TJ-II:Validation of bootstrap predictions|Validation of bootstrap predictions]]
 | [mailto:joseluis.velasco@ciemat.es J.L.Velasco]

|-
|}

== Experimental proposals, 2017 Spring==
Deadline: January 26, 2017

{| class="wikitable sortable" width="100%" border="1" cellpadding="5" cellspacing="0" style="text-align:left"
|- style="background:#FFDEAD;"
! width="10%"| '''Nr.'''
! width="60%"| '''Title'''
! width="30%"| '''Proponent(s)'''




|-
 | 1
 | [[TJ-II:Search for physical mechanisms that lead to increase of turbulence following pellet injection|Search for physical mechanisms that lead to increase of turbulence following pellet injection]]
 | [mailto:kieran.mccarthy@ciemat.es Kieran McCarthy]


|-
 | 2
 | [[TJ-II:Effect of pellet injection on the radial electric field profile of stellarators|Effect of pellet injection on the radial electric field profile of stellarators]]
 | [mailto:silvagnidavide1@gmail.com,joseluis.velasco@ciemat.es Davide Silvagni, José L. Velasco]


|-
 | 3
 | [[TJ-II:Excitation of zonal flow oscillations by energetic particles|Excitation of zonal flow oscillations by energetic particles]]
 | [mailto:edi.sanchez@ciemat.es Edi Sánchez]


|-
 | 4
 | [[TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas|Radial electric field of low-magnetic-field low-collisionality NBI plasmas]]
 | [mailto:joseluis.velasco@ciemat.es José L. Velasco]


|-
 | 5
 | [[TJ-II:Comparison of transport of on-axis and off-axis ECH-heated plasmas|Comparison of transport of on-axis and off-axis ECH-heated plasmas]]
 | [mailto:joseluis.velasco@ciemat.es,edi.sanchez@ciemat.es José L. Velasco, Edi Sánchez]
|-

 | 6
 | [[TJ-II:Impurity injection by laser blow-off: influence of main ions charge/mass on impurity confinement and transport|Impurity injection by laser blow-off: influence of main ions charge/mass on impurity confinement and transport]]
 | [mailto:belen.lopez@ciemat.es Belén López-Miranda]

|-

 | 7
 | [[TJ-II:PelletFuelling|PelletFuelling]]
 | [mailto:kieran.mccarthy@ciemat.es Kieran McCarthy]

|-

 | 8
 | [[TJ-II:Impurity density and potential asymmetries|Impurity density and potential asymmetries]]
 | [mailto:jose.regana@ciemat.es José M. García Regaña]

|-

 | 9
 | [[TJ-II:Investigation of turbulence spreading and information transfer in the TJ-II stellarator|Investigation of turbulence spreading and information transfer in the TJ-II stellarator]]
 | [mailto:boudewijn.vanmilligen@ciemat.es Boudewijn van Milligen]

|-

 | 10
 | [[TJ-II:Role of isotope effect on biasing induced transitions in the TJ-II stellarator|Role of isotope effect on biasing induced transitions in the TJ-II stellarator]]
 | [mailto:carlos.hidalgo@ciemat.es S. Ohshima]

|-

 | 11
 | [[TJ-II:Investigation of the mechanism of decoupling between energy and particle transport channels: Proposal for joint experiments in TJ-II and H-J|Investigation of the mechanism of decoupling between energy and particle transport channels: Proposal for joint experiments in TJ-II and H-J]]
 | [mailto:bing.liu@externos.ciemat.es,ulises.losada@ciemat.es Bing Liu, Ulises Losada]

|-

 | 12
 | [[TJ-II: Alfven Eigenmodes and biasing in TJ-II| Alfven Eigenmodes and biasing in TJ-II]]
 | [mailto:melnikov_07@yahoo.com A. Melnikov]

|-

 | 13
 | [[TJ-II: Potential asymmetries at low magnetic field | Potential asymmetries at low magnetic field ]]
 | [mailto:jose.regana@ciemat.es José M. García-Regaña]
|-

 | 14
 | [[TJ-II:NBI contribution to plasma fuelling|NBI contribution to plasma fuelling]]
 | [mailto:macarena.liniers@ciemat.es Macarena Liniers]

|-

 | 15
 | [[TJ-II: Investigation of plasma asymmetries in the TJ-II stellarator and comparison with Gyrokinetic simulations|Investigation of plasma asymmetries in the TJ-II stellarator and comparison with Gyrokinetic simulations]]
 | [mailto:Edi.sanchez@ciemat.es Edi Sanchez]

|-

 | 16
 | [[TJ-II:Effect of ECRH on the characteristics of Alfven Eigenmodes activity|Effect of ECRH on the characteristics of Alfven Eigenmodes activity]]
 | [mailto:alvaro.cappa@ciemat.es,enrique.ascasibar@ciemat.es,francisco.castejon@ciemat.es Álvaro Cappa, Enrique Ascasíbar, Paco Castejón]

|-

 | 17
 | [[TJ-II:Investigating the Alfvén Wave damping|Investigating the Alfvén Wave damping]]
 | [mailto:francisco.castejon@ciemat.es Paco Castejón, Álvaro Cappa, Enrique Ascasíbar]

|-

 | 18
 | [[TJ-II:L-H Transition and Isotope Effect in low magnetic ripple configurations|L-H Transition and Isotope Effect in low magnetic ripple configurations]]
 | [mailto:teresa.estrada@ciemat.es,Ulises.LosadaRodriguez@ciemat.es,Carlos.Hidalgo@ciemat.es Teresa Estrada,Ulises Losada,Carlos Hidalgo]

|-

 | 19
 | [[TJ-II:Measurements of radial correlation length and tilting of turbulent eddies by Radial Correlation Doppler Reflectometry|Measurements of radial correlation length and tilting of turbulent eddies by Radial Correlation Doppler Reflectometry]]
 | [mailto:teresa.estrada@ciemat.es,javier.pinzon@ipp.mpg.de,tim.happel@ipp.mpg.de Javier Pinzon, Tim Happel,Teresa Estrada]

|-

 | 20
 | [[TJ-II:Measurement of Te and ne of Blobs analyzing recycling helium emission in front of a poloidal limiter|Measurement of Te and ne of Blobs analyzing recycling helium emission in front of a poloidal limiter]]
 | [mailto:e.delacal@ciemat.es, Eduardo de la Cal]

|-
|}

== See also ==

* [[TJ-II:Experimental program]] (current)
* [http://intranet-fusion.ciemat.es/document-server/tj-ii-experimental-program/ Experimental programs for earlier years (2002-2016)] (Intranet, password required)

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Validation of bootstrap predictions

2018-02-12T19:36:41Z

Jlvelasco: /* Proposal title */

== Experimental campaign ==
2018 Spring

== Proposal title ==
''Validation of bootstrap predictions''.

== Name and affiliation of proponent ==
José Luis Velasco, Kieran McCarthy, Enrique Ascasíbar, Shinsuke Satake (NIFS) ''et al''.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

The bootstrap current is a neoclassical effect triggered by the radial gradients of the density and temperature in the presence of an inhomogeneous magnetic field. This current may perturb the desired magnetic configuration produced by the external coils, which is especially problematic for shearless devices, such as W7-X or TJ-II. Therefore, in order to design magnetic configurations and suitable operation scenarios, it is necessary to gain confidence on the available neoclassical predictions of bootstrap current (see e.g. <ref>Velasco 2011 PPCF</ref> and references therein). While the ion parallel flow (the ion contribution to the bootstrap current) is considered to be validated, see e.g. <ref>Arevalo 2013 NF</ref>, the electron contribution is not. Since no measurement of the electron parallel flow is available, what is left is to measure the total current or its effect on the magnetic configuration <ref>Colchin 1990 PoF, Watanabe 1995 NF, Estrada 2002 PPCF, Schmitt 2015 PoP</ref>. The proponents have participated in a recent experiment in the deuterium campaign of LHD <ref>Satake 2017 ISHW</ref>.

'''Objectives.'''

In this experiment we will create ECH plasmas with constant line-density and electron temperature during all the discharge. The working gas will be alternatively Hydrogen and Helium, and we will scan (shot-to-shot) the radial position of ECH absortion. We will measure the time evolution of the current with the Rogowski coils and two components of the magnetic field with the Motional Stark Effect diagnostic <ref>McCarthy 2015 CPP</ref>at the end of the discharge (measurements of the vacuum field will also be necessary). We will then compare the measurements with neoclassical simulations.

Off-axis heating should lead to lower electron temperatures, and use of Helium to larger effective charge. Both things should contribute to a faster equilibration of the total current and thus make the measurements easier. We will consider adding short gas puffs of impurities (e.g. N) in order to further accelerate the time evolution of the current.

== If applicable, International or National funding project or entity ==
EUROfusion WP18.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 2 day (1 H, 1 He)
* Essential diagnostic systems:

We will measure:

- The time evolution of the total current <math><I_t(t)></math> with the Rogowsky coils.

- Two components of the magnetic field at the end of the discharge (when <math><I_t(t)></math> has converged) with the Motional Stark Effect

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS) and the He beam.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density and electron temperature as measured by ECE. We will scan the position of one of the gyrotrons in order to change the electron temperature profile.
* Specific requirements on wall conditioning if any: Lithium coating if considered necessary for stable plasmas
* External users: need a local computer account for data access: no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

See also

http://fusionsites.ciemat.es/jlvelasco/files/notes/ICasal_informe.pdf

and

http://fusionsites.ciemat.es/jlvelasco/files/presentations/velasco_etal_bootstrap.pdf

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Validation of bootstrap predictions

2018-02-12T19:35:33Z

Jlvelasco:

== Experimental campaign ==
2018 Spring

== Proposal title ==
''Comparison of bootstrap predictions with Motional Stark Effect and Rogowski Coils''.

== Name and affiliation of proponent ==
José Luis Velasco, Kieran McCarthy, Enrique Ascasíbar, Shinsuke Satake (NIFS) ''et al''.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

The bootstrap current is a neoclassical effect triggered by the radial gradients of the density and temperature in the presence of an inhomogeneous magnetic field. This current may perturb the desired magnetic configuration produced by the external coils, which is especially problematic for shearless devices, such as W7-X or TJ-II. Therefore, in order to design magnetic configurations and suitable operation scenarios, it is necessary to gain confidence on the available neoclassical predictions of bootstrap current (see e.g. <ref>Velasco 2011 PPCF</ref> and references therein). While the ion parallel flow (the ion contribution to the bootstrap current) is considered to be validated, see e.g. <ref>Arevalo 2013 NF</ref>, the electron contribution is not. Since no measurement of the electron parallel flow is available, what is left is to measure the total current or its effect on the magnetic configuration <ref>Colchin 1990 PoF, Watanabe 1995 NF, Estrada 2002 PPCF, Schmitt 2015 PoP</ref>. The proponents have participated in a recent experiment in the deuterium campaign of LHD <ref>Satake 2017 ISHW</ref>.

'''Objectives.'''

In this experiment we will create ECH plasmas with constant line-density and electron temperature during all the discharge. The working gas will be alternatively Hydrogen and Helium, and we will scan (shot-to-shot) the radial position of ECH absortion. We will measure the time evolution of the current with the Rogowski coils and two components of the magnetic field with the Motional Stark Effect diagnostic <ref>McCarthy 2015 CPP</ref>at the end of the discharge (measurements of the vacuum field will also be necessary). We will then compare the measurements with neoclassical simulations.

Off-axis heating should lead to lower electron temperatures, and use of Helium to larger effective charge. Both things should contribute to a faster equilibration of the total current and thus make the measurements easier. We will consider adding short gas puffs of impurities (e.g. N) in order to further accelerate the time evolution of the current.

== If applicable, International or National funding project or entity ==
EUROfusion WP18.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 2 day (1 H, 1 He)
* Essential diagnostic systems:

We will measure:

- The time evolution of the total current <math><I_t(t)></math> with the Rogowsky coils.

- Two components of the magnetic field at the end of the discharge (when <math><I_t(t)></math> has converged) with the Motional Stark Effect

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS) and the He beam.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density and electron temperature as measured by ECE. We will scan the position of one of the gyrotrons in order to change the electron temperature profile.
* Specific requirements on wall conditioning if any: Lithium coating if considered necessary for stable plasmas
* External users: need a local computer account for data access: no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

See also

http://fusionsites.ciemat.es/jlvelasco/files/notes/ICasal_informe.pdf

and

http://fusionsites.ciemat.es/jlvelasco/files/presentations/velasco_etal_bootstrap.pdf

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Validation of bootstrap predictions

2018-02-12T19:33:44Z

Jlvelasco: Created page with "== Experimental campaign == 2018 Spring == Proposal title == ''Comparison of bootstrap predictions with Motional Stark Effect and Rogowski Coils'' == Name and affiliation of..."

== Experimental campaign ==
2018 Spring

== Proposal title ==
''Comparison of bootstrap predictions with Motional Stark Effect and Rogowski Coils''

== Name and affiliation of proponent ==
José Luis Velasco, Kieran McCarthy, Enrique Ascasíbar, Shinsuke Satake (NIFS) et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

The bootstrap current is a neoclassical effect triggered by the radial gradients of the density and temperature in the presence of an inhomogeneous magnetic field. This current may perturb the desired magnetic configuration produced by the external coils, which is especially problematic for shearless devices, such as W7-X or TJ-II. Therefore, in order to design magnetic configurations and suitable operation scenarios, it is necessary to gain confidence on the available neoclassical predictions of bootstrap current (see e.g. <ref>Velasco 2011 PPCF</ref> and references therein). While the ion parallel flow (the ion contribution to the bootstrap current) is considered to be validated, see e.g. <ref>Arevalo 2013 NF</ref>, the electron contribution is not. Since no measurement of the electron parallel flow is available, what is left is to measure the total current or its effect on the magnetic configuration <ref>Colchin 1990 PoF, Watanabe 1995 NF, Estrada 2002 PPCF, Schmitt 2015 PoP</ref>. The proponents have participated in a recent experiment in the deuterium campaign of LHD <ref>Satake 2017 ISHW</ref>.

'''Objectives.'''

In this experiment we will create ECH plasmas with constant line-density and electron temperature during all the discharge. The working gas will be alternatively Hydrogen and Helium, and we will scan (shot-to-shot) the radial position of ECH absortion. We will measure the time evolution of the current with the Rogowski coils and two components of the magnetic field with the Motional Stark Effect diagnostic <ref>McCarthy 2015 CPP</ref>at the end of the discharge (measurements of the vacuum field will also be necessary). We will then compare the measurements with neoclassical simulations.

Off-axis heating should lead to lower electron temperatures, and use of Helium to larger effective charge. Both things should contribute to a faster equilibration of the total current and thus make the measurements easier. We will consider adding short gas puffs of impurities (e.g. N) in order to further accelerate the time evolution of the current.

== If applicable, International or National funding project or entity ==
EUROfusion WP18.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 2 day (1 H, 1 He)
* Essential diagnostic systems:

We will measure:

- The time evolution of the total current <math><I_t(t)></math> with the Rogowsky coils.

- Two components of the magnetic field at the end of the discharge (when <I_t(t)> has converged) with the Motional Stark Effect

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS) and the He beam.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- ...

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density and electron temperature as measured by ECE. We will scan the position of one of the gyrotrons in order to change the electron temperature profile.
* Specific requirements on wall conditioning if any: Lithium coating if considered necessary for stable plasmas
* External users: need a local computer account for data access: no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

See also

http://fusionsites.ciemat.es/jlvelasco/files/notes/ICasal_informe.pdf

and

http://fusionsites.ciemat.es/jlvelasco/files/presentations/velasco_etal_bootstrap.pdf

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-25T12:43:40Z

Jlvelasco: /* Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages) */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial electric field of low-magnetic-field low-collisionality NBI plasmas''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas with NBI in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength. Additionally, over the NBI-created plasmas, we will check whether additional ECH power can be absorbed and this has an effect on impurities.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 successful day (which may require more than 1 day, as HIBP and Doppler will have to be calibrated).
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially. <math>B=0.6T</math>.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-24T17:56:23Z

Jlvelasco:

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the electron temperature profile and the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2016 IAEA/NF</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>Baldzuhn 1999 PPCF</ref>. The evolution of the temperature profile is itself relevant, as pre-cooling with a pellet is thought to be a possible strategy for increasing the fuelling efficiency of pellets. We will characterise it and we will try to model it with neoclassical simulations.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the time evolution of the profiles is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3,ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI plasmas with approximately constant line-averaged density.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no earlier than 01-03-2017 and no later than 01-04-2017.

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Comparison of transport of on-axis and off-axis ECH-heated plasmas

2017-01-24T17:53:07Z

Jlvelasco: /* Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages) */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Comparison of transport of on-axis and off-axis ECH-heated plasmas''

== Name and affiliation of proponent ==
José Luis Velasco, Edi Sánchez, Teresa Estrada, Álvaro Cappa, the HIBP team et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

Particle transport of ECH plasmas<ref>Yokoyama 2005 NF</ref> is not well understood, as neoclassical simulations seem to overestimate the radial particle flux of on-axis heated ECH-plasmas; on the other hand, preliminary analyses show that this problem does not exist for off-axis ECH-heated plasmas. A comparison between these two situations (including neoclassical and gyrokinetic simulations and corresponding measurements) may shed some light on this problem, probably relevant for assessing the fuelling requirements of reactor plasmas<ref>Maassberg 1999 NF</ref>. Even if the results along this line are finally not conclusive, the experimental and theoretical characterization of turbulence with different profiles (peaked/hollow <math>T_e</math> with hollow/peaked <math>n_e</math>) is itself relevant. We will also have a look at impurity transport, as off-axis heated plasmas have been predicted to have negative radial electric field in the core and positive radial electric field closer to the edge, contrary to typical ECH plasmas.

'''Objectives.'''

In this experiment we plan to scan (shot-to-shot) the radial position of ECH absortion and measure:

* Electron density and temperature profile.
* Radial electric field profile.
* ....

We will compare the measurements with neoclassical and gyrokinetic simulations.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3, WP17.S2.1.8,ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The profiles of the electrostatic potential.

- ...

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density. From previous experiments, we have on-axis heated plasmas, and plasmas with one gyrotron on-axis and the other off-axis, so we will focus in totally off-axis heating.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-24T17:50:20Z

Jlvelasco: /* Description of required resources */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial electric field of low-magnetic-field low-collisionality NBI plasmas''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 successful day (which may require more than 1 day, as HIBP and Doppler will have to be calibrated).
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially. <math>B=0.6T</math>.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-22T18:13:21Z

Jlvelasco: /* Description of required resources */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial electric field of low-magnetic-field low-collisionality NBI plasmas''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 successful day (which may require more than 1 day, as HIBP and Doppler will have to be calibrated).
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially. B=0.6T</math>.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Comparison of transport of on-axis and off-axis ECH-heated plasmas

2017-01-22T17:57:47Z

Jlvelasco: /* Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages) */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Comparison of transport of on-axis and off-axis ECH-heated plasmas''

== Name and affiliation of proponent ==
José Luis Velasco, Edi Sánchez, Teresa Estrada, Álvaro Cappa, the HIBP team et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

Particle transport of ECH plasmas<ref>Yokoyama 2005 NF</ref> is not well understood, as neoclassical simulations seem to overestimate the radial particle flux of on-axis heated ECH-plasmas; on the other hand, preliminary analyses show that this problem does not exist for off-axis ECH-heated plasmas. A comparison between these two situations (including neoclassical and gyrokinetic simulations and corresponding measurements) may shed some light on this problem, probably relevant for assessing the fuelling requirements of reactor plasmas<ref>Maassberg 1999 NF</ref>. Even if the results along this line are finally not conclusive, the experimental and theoretical characterization of turbulence with different profiles (peaked/hollow <math>T_e</math> with hollow/peaked <math>n_e</math>) is itself relevant.

'''Objectives.'''

In this experiment we plan to scan (shot-to-shot) the radial position of ECH absortion and measure:

* Electron density and temperature profile.
* Radial electric field profile.
* ....

We will compare the measurements with neoclassical and gyrokinetic simulations.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3, WP17.S2.1.8,ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The profiles of the electrostatic potential.

- ...

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density. From previous experiments, we have on-axis heated plasmas, and plasmas with one gyrotron on-axis and the other off-axis, so we will focus in totally off-axis heating.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Comparison of transport of on-axis and off-axis ECH-heated plasmas

2017-01-22T17:56:29Z

Jlvelasco:

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Comparison of transport of on-axis and off-axis ECH-heated plasmas''

== Name and affiliation of proponent ==
José Luis Velasco, Edi Sánchez, Teresa Estrada, Álvaro Cappa, the HIBP team et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''

Particle transport of ECH plasmas is not well understood<ref>Dinklage 2013 NF</ref>, as neoclassical simulations seem to overestimate the radial particle flux of on-axis heated ECH-plasmas; on the other hand, preliminary analyses show that this problem does not exist for off-axis ECH-heated plasmas. A comparison between these two situations (including neoclassical and gyrokinetic simulations and corresponding measurements) may shed some light on this problem, probably relevant for assessing the fuelling requirements of reactor plasmas<ref>Maassberg 1999 NF</ref>. Even if the results along this line are finally not conclusive, the experimental and theoretical characterization of turbulence with different profiles (peaked/hollow <math>T_e</math> with hollow/peaked <math>n_e</math>) is itself relevant.

'''Objectives.'''

In this experiment we plan to scan (shot-to-shot) the radial position of ECH absortion and measure:

* Electron density and temperature profile.
* Radial electric field profile.
* ....

We will compare the measurements with neoclassical and gyrokinetic simulations.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3, WP17.S2.1.8,ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The profiles of the electrostatic potential.

- ...

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density. From previous experiments, we have on-axis heated plasmas, and plasmas with one gyrotron on-axis and the other off-axis, so we will focus in totally off-axis heating.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-22T17:48:26Z

Jlvelasco: /* Description of required resources */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial electric field of low-magnetic-field low-collisionality NBI plasmas''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially. B=0.6T</math>.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-22T17:47:14Z

Jlvelasco: /* Proposal title */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial electric field of low-magnetic-field low-collisionality NBI plasmas''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-22T17:46:32Z

Jlvelasco: /* Proposal title */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial_electric_field_of_low-magnetic-field_low-collisionality_NBI_plasmas''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Radial electric field of low-magnetic-field low-collisionality NBI plasmas

2017-01-22T17:45:43Z

Jlvelasco: Created page with "== Experimental campaign == 2017 Spring == Proposal title == ''Radial_electric_field_of_low-magnetic-field_low-collisionality_NBI_plasmas&action=edit&redlink=1'' == Name and..."

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Radial_electric_field_of_low-magnetic-field_low-collisionality_NBI_plasmas&action=edit&redlink=1''

== Name and affiliation of proponent ==
José Luis Velasco et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Impurity hole plasmas are characterized by having negative radial electric field that is smaller in absolute value than the ion tempererature gradient<ref>Velasco 2017 NF</ref>. In this work, we also showed data from NBI-only plasmas of TJ-II: as the density was reduced, the core electrostatic potential got closer to zero. In this experiment, we plan to make the radial electric field even smaller by creating the plasmas in configurations of reduced magnetic field strength, since <math>E_r</math> should be proportional to <math>B</math> for impurity-hole-relevant plasmas.

'''Objectives.'''
In this experiment we plan to measure the ion temperature and radial electric field, and the plasma profiles of comparable NBI-only plasmas with different magnetic field strength.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS). The time instant should be that of minimum <math><n_e></math>.

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field with reflectometry.

- The time evolution of the electrostatic potential and its radial profile: one HIBP should be fixed in the core region and the other one scanning radially.

* Type of plasmas (heating configuration): plasmas created with NBI without ECH; the two NBIs should inject sequentially.
* Specific requirements on wall conditioning if any: inmediately after lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): better before 01-04-2017

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Comparison of transport of on-axis and off-axis ECH-heated plasmas

2017-01-22T17:29:46Z

Jlvelasco: Created page with "== Experimental campaign == 2017 Spring == Proposal title == ''Comparison of transport of on-axis and off-axis ECH-heated plasmas'' == Name and affiliation of proponent == J..."

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Comparison of transport of on-axis and off-axis ECH-heated plasmas''

== Name and affiliation of proponent ==
José Luis Velasco, Edi Sánchez, Teresa Estrada, Álvaro Cappa, the HIBP team et al.

== Details of contact person at LNF (if applicable) ==

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Particle transport of ECH plasmas is not well understood, as neoclassical simulations seem to overestimate the radial particle flux of on-axis heated ECH-plasmas; on the other hand, preliminary analyses show that this problem does not exist for off-axis ECH-heated plasmas. A comparison between these two situations (including neoclassical and gyrokinetic simulations and corresponding measurements) may shed some light on this problem, probably relevant for assessing the fuelling requirements of reactor plasmas. Even if the results along this line are finally not conclusive, the experimental and theoretical characterization of turbulence with different profiles (peaked/hollow <math>T_e</math> with hollow/peaked<math>n_e</math>) is itself relevant.

'''Objectives.'''
In this experiment we plan to scan (shot-to-shot) the radial position of ECH absortion and measure:

* Electron density and temperature profile.
* Radial electric field profile.
* ....

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3, WP17.S2.1.8,ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The profiles of the electrostatic potential.

- ...

* Type of plasmas (heating configuration): ECH plasmas with constant line-averaged density. From previous experiments, we have on-axis heated plasmas, and plasmas with one gyrotron on-axis and the other off-axis, so we will focus in totally off-axis heating.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy):

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-22T17:21:18Z

Jlvelasco:

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2016 IAEA/NF</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>Baldzuhn 1999 PPCF</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3,ENE2015-70142-P

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI plasmas with approximately constant line-averaged density.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no earlier than 01-03-2017 and no later than 01-04-2017.

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Experimental proposals

2017-01-22T17:08:33Z

Jlvelasco:

TJ-II:Experimental proposals

2017-01-22T17:07:54Z

Jlvelasco:

TJ-II:Experimental proposals

2017-01-22T17:06:37Z

Jlvelasco:

TJ-II:Experimental proposals

2017-01-18T21:42:19Z

Jlvelasco: /* Experimental proposals, 2017 Spring */

TJ-II:Experimental proposals

2017-01-18T21:27:50Z

Jlvelasco:

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-18T21:26:50Z

Jlvelasco:

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2016 IAEA/NF</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>Baldzuhn 1999 PPCF</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI plasmas with approximately constant line-averaged density.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no earlier than 01-03-2017 and no later than 01-04-2017.

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-18T21:23:56Z

Jlvelasco: /* Preferred dates and degree of flexibility */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2015 ISWH, McCarthy 2016 EPS</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>[Baldzuhn 1999 PPCF]</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Baldzuhn 1999 PPCF, Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI plasmas with approximately constant line-averaged density.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no earlier than 01-03-2017 and no later than 01-04-2017.

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-18T21:22:31Z

Jlvelasco: /* Description of required resources */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2015 ISWH, McCarthy 2016 EPS</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>[Baldzuhn 1999 PPCF]</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1 day.
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Baldzuhn 1999 PPCF, Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI plasmas with approximately constant line-averaged density.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no February

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-18T21:22:03Z

Jlvelasco: /* Description of required resources */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2015 ISWH, McCarthy 2016 EPS</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>[Baldzuhn 1999 PPCF]</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation: 1
* Essential diagnostic systems:
We will measure:

- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Baldzuhn 1999 PPCF, Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI plasmas with approximately constant line-averaged density.
* Specific requirements on wall conditioning if any: recent lithium-coating for good density control.
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no February

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-18T21:20:29Z

Jlvelasco: /* Proposal title */

== Experimental campaign ==
2017 Spring

== Proposal title ==
''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2015 ISWH, McCarthy 2016 EPS</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>[Baldzuhn 1999 PPCF]</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation:
* Essential diagnostic systems:
- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Baldzuhn 1999 PPCF, Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI
* Specific requirements on wall conditioning if any: recent lithium
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no February

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

TJ-II:Effect of pellet injection on the radial electric field profile of stellarators

2017-01-18T21:20:07Z

Jlvelasco: Created page with "== Experimental campaign == 2017 Spring == Proposal title == '''Effect of pellet injection on the radial electric field profile of stellarators'' == Name and affiliation of ..."

== Experimental campaign ==
2017 Spring

== Proposal title ==
'''Effect of pellet injection on the radial electric field profile of stellarators''

== Name and affiliation of proponent ==
Davide Silvagni, Kieran McCarthy, José L. Velasco, the HIBP team
the pellet team, et al.

== Details of contact person at LNF (if applicable) ==
José L. Velasco

== Description of the activity, including motivation/objectives and experience of the proponent (typically one-two pages)==
'''Motivation.'''
Pellet injection modifies in a very abrupt manner the density and electron temperature profiles, see e.g. <ref>McCarthy 2015 ISWH, McCarthy 2016 EPS</ref>, and this is known to affect radial transport (at least transiently) in such a way that can be described by neoclassical theory, see e.g. <ref>Velasco 2016 PPCF</ref>. In particular, through modification of the density and electron temperature gradients, it can affect the radial electric field profile, which is set by ambipolarity of the neoclassical fluxes. Positive radial electric fields, connected to hollow density profiles, have been found in the Large Helical Device after injection of a pellet close to the edge <ref>Dinklage 2016 IAEA</ref>. This would be a manifestation of the well-known positive ion-root feature <ref>[Baldzuhn 1999 PPCF]</ref>.

'''Objectives.'''
In this experiment we plan to inject pellets into steady-state plasmas and characterize the variation of the radial gradients of:

* Electron density.
* Electron temperature.
* Electrostatic potential.

The goal is to check whether the change of radial electric field in response to the change of density and electron temperature gradients is compliant with neoclassical predictions.

== If applicable, International or National funding project or entity ==
EUROfusion WP17.S1.A2, WP17.S1.A3

== Description of required resources ==
Required resources:
* Number of plasma discharges or days of operation:
* Essential diagnostic systems:
- The time evolution of the line-averaged density <math><n_e(t)></math> with interferometry.

- The radial profiles of electron density <math>n_e(r,t_0)</math> and temperature <math>T_e(r,t_0)</math> at one time instant <math>t_0</math> with Thomson Scattering (TS).

- The time evolution of the electron temperature profile <math>T_e(r,t)</math> with Electron Cyclotron Emission (ECE), when available, calibrated with TS.

- The time evolution of the ion temperature in the core and in an outer radial position, <math>T_i(r/a=0.2,t)</math> and <math>T_i(r/a~=0.6,t)</math>, with the Neutral Particle Analyzer (NPA).

- The time evolution of the radial electric field in the gradient region <math>E_r(r/a~=0.65,t)</math>, with reflectometry.

- The time evolution of the electrostatic potential in the core region <math>\Phi(r<0.5,t)</math> with the double Heavy Ion Beam Prove (HIBP). For this:

o one of the HIBPs will be scanning from <math>r/a=0.2</math> to <math>r/a=0.5</math>.

o the other HIBP will be kept fixed at <math>r/a~0.2</math>.

- The ablation process will be detected with <math>H_{alpha}</math> monitors.NC simulations will be performed with analytical methods in the plateau limit and with DKES.

In principle, a positive electric field should lead outward convection for impurities, but this was not the case of W7-AS plasmas with core electron root and positive ion root at intermediate radial positions <ref>Baldzuhn 1999 PPCF, Hirsch 2008 PPCF</ref>. We will nevertheless keep an eye on the radiation signals from the bolometers as they can provide (when normalized by the electron density) an indication of the impurity content of the plasma.

* Type of plasmas (heating configuration): NBI
* Specific requirements on wall conditioning if any: recent lithium
* External users: need a local computer account for data access: yes/no
* Any external equipment to be integrated? Provide description and integration needs:

== Preferred dates and degree of flexibility ==
Preferred dates: (format dd-mm-yyyy): no February

== References ==
<references />

<hr>
[[TJ-II:Experimental proposals|Back to list of experimental proposals]]

[[Category:TJ-II internal documents]]
[[Category:TJ-II experimental proposals]]

Coordinated Working Group Meeting

2016-10-18T13:55:59Z

Jlvelasco: 16th CWGM, Madrid (2017).

The [[Coordinated Working Group]] Meeting (CWGM) implements and coordinates international collaborations in [[Stellarator|stellarator-heliotron]] research.
The work is intended to contribute to the [[Fusion_databases|International Stellarator-Heliotron Confinement (Profile) Database, ISH-C(P)DB]].
The Coordinated Working Group Meeting and related database activities ISHPDB are being conducted under the auspices of the IEA Implementing Agreement of Development of Stellarator/Heliotron Concepts (2.10.1992).

== List of meetings ==

* [http://p-grp.nucleng.kyoto-u.ac.jp/ktscwgm2006/ 1st CWGM, Kyoto 2006]
* [http://www.ipp.mpg.de/~dinklage/CWGM2007/cwgm.html 2nd CWGM, Greifswald 2007]
* [http://ishcdb.nifs.ac.jp/program.html 3rd CWGM, Toki, 2007]
* [http://labfus.ciemat.es/cwgm4/index.htm 4th CWGM, Madrid, 2008]
* [http://www.ipf.uni-stuttgart.de/cwgm/index.html 5th CWGM, Stuttgart, 2009]
* [http://www.pppl.gov/conferences/2009/ISHW09/CWGM.html 6th CWGM, 2009]
* [http://www.ipp.mpg.de/~dinklage/CWGM7/ 7th CWGM, Greifswald, 2010]
* [http://ishcdb.nifs.ac.jp/cwgm8.html 8th CWGM, Toki, 2011]
* [http://iscdb.nifs.ac.jp/cwgm9.html 9th CWGM, Canberra, Australia, January 28, 2012]
* [http://ishcdb.nifs.ac.jp/cwgm10.html 10th CWGM, Greifswald, Germany, 6-8 June, 2012]
* [http://fusionsites.ciemat.es/cwgm11 11th CWGM, Madrid, Spain, 11-13 March 2013]
* [http://ishcdb.nifs.ac.jp/CWGM12/index.html 12th CWGM, Padova, Italy, 20 September 2013] (at the 19th [[International Stellarator and Heliotron Workshop]])
* [http://ishcdb.nifs.ac.jp/CWGM13/index.html 13th CWGM, Kyoto, Japan, 26-28 February 2014]
* [http://ishcdb.nifs.ac.jp/CWGM14/index.html 14th CWGM, Warsaw, Poland, 17-19 June, 2015]
* [http://www.ipp.mpg.de/cwgm 15th CWGM, Greifswald, Germany, 21-23 March, 2016]
* [http://fusionsites.ciemat.es/cwgm16 16th CWGM, Madrid, Spain, 18-20 January, 2017]

[[Category:Conferences]]

Fusion databases

2016-05-24T16:41:34Z

Jlvelasco: Updated ISHDB links and contact.

= Fusion Devices =
== Stellarators/Heliotrons ==
*[https://ishpdb.ipp-hgw.mpg.de/ ISHPDB ('''I'''nternational '''S'''tellarator/'''H'''eliotron '''P'''rofile '''D'''ata'''b'''ase)] (contains the International Stellarator/Heliotron Confinement Database<ref>[[doi:10.1088/0029-5515/49/6/065016|A. Weller, K.Y. Watanabe, S. Sakakibara, et al, ''International Stellarator/Heliotron Database progress on high-beta confinement and operational boundaries'', Nucl. Fusion '''49''' (2009) 065016]]</ref>)
*[http://ishpdb.nifs.ac.jp/index.html ISHPDB NIFS mirror]
[mailto:dinklage@ipp.mpg.de;joseluis.velasco@ciemat.es;yokoyama@lhd.nifs.ac.jp Contact] for the above databases
*[http://h1nf.anu.edu.au/collaborate/mddb/ MDDB (MHD Documentation Database)]

== Tokamaks ==
* [http://efdasql.ipp.mpg.de/HmodePublic/ International Global H-Mode Confinement Database]
* [http://efdasql.ipp.mpg.de/Igd/confexp.htm ITER Confinement Database and Modeling Expert Group]
* [http://tokamak-profiledb.ccfe.ac.uk/ The International Multi-Tokamak Confinement Profile Database]

= Physics Databases =
== Atomic Data ==
* [http://www.adas.ac.uk/ Atomic Data and Analysis Structure]
* [http://www.adas-fusion.eu/ ADAS-EU]
* [http://physics.nist.gov/PhysRefData/ASD/index.html NIST Atomic Spectra Database]
* [http://www-amdis.iaea.org/w/index.php/Main_Page IAEA Knowledge Base for Atomic, Molecular and Plasma-material Interaction Data for Fusion]

== Constants ==

* [http://physics.nist.gov/cuu/Constants/index.html CODATA Internationally recommended values of the Fundamental Physical Constants]

= References =
<references />

Coordinated Working Group Meeting

2016-03-19T17:40:36Z

Jlvelasco: Added link to CWGM15

The [[Coordinated Working Group]] Meeting (CWGM) implements and coordinates international collaborations in [[Stellarator|stellarator-heliotron]] research.
The work is intended to contribute to the [[Fusion_databases|International Stellarator-Heliotron Confinement (Profile) Database, ISH-C(P)DB]].
The Coordinated Working Group Meeting and related database activities ISHPDB are being conducted under the auspices of the IEA Implementing Agreement of Development of Stellarator/Heliotron Concepts (2.10.1992).

== List of meetings ==

* [http://p-grp.nucleng.kyoto-u.ac.jp/ktscwgm2006/ 1st CWGM, Kyoto 2006]
* [http://www.ipp.mpg.de/~dinklage/CWGM2007/cwgm.html 2nd CWGM, Greifswald 2007]
* [http://ishcdb.nifs.ac.jp/program.html 3rd CWGM, Toki, 2007]
* [http://labfus.ciemat.es/cwgm4/index.htm 4th CWGM, Madrid, 2008]
* [http://www.ipf.uni-stuttgart.de/cwgm/index.html 5th CWGM, Stuttgart, 2009]
* [http://www.pppl.gov/conferences/2009/ISHW09/CWGM.html 6th CWGM, 2009]
* [http://www.ipp.mpg.de/~dinklage/CWGM7/ 7th CWGM, Greifswald, 2010]
* [http://ishcdb.nifs.ac.jp/cwgm8.html 8th CWGM, Toki, 2011]
* [http://iscdb.nifs.ac.jp/cwgm9.html 9th CWGM, Canberra, Australia, January 28, 2012]
* [http://ishcdb.nifs.ac.jp/cwgm10.html 10th CWGM, Greifswald, Germany, 6-8 June, 2012]
* [http://www.cwgm11.ciemat.es 11th CWGM, Madrid, Spain, 11-13 March 2013]
* [http://ishcdb.nifs.ac.jp/CWGM12/index.html 12th CWGM, Padova, Italy, 20 September 2013] (at the 19th [[International Stellarator and Heliotron Workshop]])
* [http://ishcdb.nifs.ac.jp/CWGM13/index.html 13th CWGM, Kyoto, Japan, 26-28 February 2014]
* [http://ishcdb.nifs.ac.jp/CWGM14/index.html 14th CWGM, Warsaw, Poland, 17-19 June, 2015]
* [http://www.ipp.mpg.de/cwgm 15th CWGM, Greifswald, Germany, 21-23 March, 2016]

[[Category:Conferences]]