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TJ-II is a flexible Heliac installed at Spain's [[National Fusion Laboratory]]. It is currently operational. | [[File:TJII_model.jpg|500px|thumb|right|TJ-II Model]] | ||
TJ-II is a flexible Heliac installed at Spain's [[Laboratorio Nacional de Fusión|National Fusion Laboratory]]. | |||
It is one of Spain's [https://www.ciencia.gob.es/Organismos-y-Centros/Infraestructuras-Cientificas-y-Tecnicas-Singulares-ICTS.html Unique Scientific and Technical Infrastructures]. | |||
It is currently operational. | |||
== History == | == History == | ||
The flexible Heliac TJ-II was designed on the basis of calculations performed by the team of physicists and engineers of [[CIEMAT]], in collaboration with the Oak Ridge National Laboratory (ORNL, USA) and the Institut für PlasmaPhysik at Garching (IPP, Germany). The TJ-II project received preferential support from [[Euratom]] for phase I (Physics) in 1986 and for phase II (Engineering) in 1990. The construction of this flexible Heliac was carried out in parts according to its constitutive elements, which were commissioned to various European companies, although 60% of the investments reverted back to Spanish companies. | [[File:Foto_grupo_Fusion_1996.jpg|300px|thumb|left|TJ-II and the TJ-II Team in 1996]] | ||
The flexible Heliac TJ-II was designed on the basis of calculations performed by the team of physicists and engineers of [[CIEMAT]], in collaboration with the Oak Ridge National Laboratory ([http://en.wikipedia.org/wiki/ORNL ORNL], USA) and the Institut für PlasmaPhysik at Garching ([http://en.wikipedia.org/wiki/Max-Planck-Institut_f%C3%BCr_Plasmaphysik IPP], Germany). | |||
<ref>T.C. Hender et al, ''Studies of a flexible heliac configuration'', [https://www.osti.gov/biblio/6007697-studies-flexible-heliac-configuration Report ORNL/TM-10374 (1987) OSTI ID: 6007697]</ref>, | |||
<ref>A. Perea et al., "Physics Issues in the Design of TJ-II, Proc. 12th European Conf. Controlled Fusion and Plasma Physics, Budapest, Hungary, 1985, [http://libero.ipp.mpg.de/libero/PDF/EPS_12_Vol1_1985.pdf ECA Vol. 9F, Part I, p. 433], European Physical Society (1985)</ref>. | |||
The TJ-II project received preferential support from [[Euratom]] for phase I (Physics) in 1986<ref>Application for EURATOM preferential support (Phase I) - TJ-II EXPERIMENT, [https://info.fusion.ciemat.es/InternalReport/fusion_1985.pdf Technical report, Asociación EURATOM/CIEMAT, 1985]</ref> and for phase II (Engineering) in 1990<ref>Application for EURATOM preferential support (Phase II) - TJ-II EXPERIMENT, [https://info.fusion.ciemat.es/InternalReport/fusion_1989b.pdf Technical report, Asociación EURATOM/CIEMAT, 1989]</ref>. The [[TJ-II:Construction|construction of this flexible Heliac]] was carried out in parts according to its constitutive elements, which were commissioned to various European companies, although 60% of the investments reverted back to Spanish companies. | |||
The first plasma was produced in 1997.<ref>[http://www.ciemat.es/vertices/vertices-292017/Vertices29/pdf/VERTICES29.pdf Special issue of CIEMAT's magazine ''Vertices''] commemorating 20 years of experiments (December, 2017)</ref> | |||
== Precedents == | == Precedents == | ||
TJ-II is the third magnetic confinement device in a series. In 1983, the device [[TJ-I]] was taken into operation. | TJ-II is the third magnetic confinement device in a series. In 1983, the device [[TJ-I]] was taken into operation. | ||
The denomination of this device is due to the abbreviation of "Tokamak de la | The denomination of this device is due to the abbreviation of "Tokamak de la Junta de Energía Nuclear", this being the former denomination of [[CIEMAT]]. The abbreviation was maintained for successive devices for administrative reasons. | ||
In 1994, the torsatron [[TJ-IU]] was taken into operation. This was the first magnetic confinement device entirely built in Spain. Currently, [[TJ-IU]] is located at the University of Stuttgart in Germany under the name of [[TJ-K]]. | In 1994, the torsatron [[TJ-IU]] was taken into operation. This was the first magnetic confinement device entirely built in Spain. Currently, [[TJ-IU]] is located at the [http://www.ipf.uni-stuttgart.de/index_e.html University of Stuttgart] in Germany under the name of [[TJ-K]] (the 'K' stands for Kiel, its first location in Germany, before arriving in Stuttgart). | ||
== Description == | == Description == | ||
[[File:TJ-II_3D_perspective.jpg|300px|thumb|right|TJ-II perspective view]] | |||
TJ-II | In TJ-II, the magnetic trap is obtained by means of [[TJ-II:Coil system|various sets of coils]] that completely determine the magnetic surfaces before plasma initiation. The toroidal field is created by 32 coils. The three-dimensional twist of the central axis of the configuration is generated by means of two central coils: one circular and one helical. The horizontal position of the plasma is controlled by the vertical field coils. The combined action of these magnetic fields generate bean-shaped magnetic surfaces that guide the particles of the plasma so that they do not collide with the [[TJ-II:Vacuum system|vacuum vessel]] wall. | ||
TJ-II discharges last around 0.25 s, with a repetition frequency of about 7 minutes. | |||
The objective of the experimental program of TJ-II is to investigate the physics of a device with a helical magnetic axis | {| class="wikitable" align="center" border="1" | ||
!''Parameter'' !!''Value''!!''Unit'' | |||
|- | |||
|Major radius, ''R<sub>0</sub>'': || 1.5 || m | |||
|- | |||
|Minor radius, ''a'': || < 0.22 || m | |||
|- | |||
|Plasma volume, ''V'': || 1 || m<sup>3</sup> | |||
|- | |||
|Field periods: || 4 || | |||
|- | |||
|[[TJ-II:Coil system|TF coils]]: || 32 || | |||
|- | |||
|Number of ports: || 104 || | |||
|- | |||
|Rotational transform, ''ι/2π'': || 0.9 - 2.5 || | |||
|- | |||
|Magnetic field on axis, ''B<sub>0</sub>'': || ~1 || T | |||
|- | |||
|ECRH heating power, ''P<sub>ECRH</sub>'': || < 600 || kW | |||
|- | |||
|NBI heating power, ''P<sub>NBI</sub>'': || < 2 || MW | |||
|- | |||
|Pulse length: || < 200 || ms | |||
|} | |||
== Goals and Research == | |||
The objective of the experimental program of TJ-II is to investigate the physics of a device with a helical magnetic axis having a great flexibility in its magnetic configuration, and to contribute to the international effort regarding the study of magnetic confinement devices for fusion. | |||
Also refer to [[LNF:Plasma Physics]]. | |||
== Operation == | == Operation == | ||
The electric energy required for a TJ-II discharge is obtained from a [[flywheel generator]]. | * A [[TJ-II:Vacuum system|vacuum system]] controls the pressure inside the vacuum vessel. | ||
The coils are cooled by means of a [[cooling system]]. | * The electric energy required for a TJ-II discharge is obtained from a [[TJ-II:Power supply|flywheel generator]]. | ||
* The [[TJ-II:Coil system|coils]] are cooled by means of a [[TJ-II:Cooling system|cooling system]]. | |||
* An extensive set of systems is available to perform [[TJ-II:Plasma Wall Interaction|plasma wall conditioning]]. | |||
* Two movable [[TJ-II:Limiter|limiters]] can be used to limit the plasma. | |||
* A [[TJ-II:Biasing probe|biasing probe]] can be used to apply a bias potential at the edge. | |||
* A [[TJ-II:Paddle|mechanical paddle]] is used to suppress runaway electrons during current ramp-up and ramp-down. | |||
== Heating == | == Heating and fuelling == | ||
In order to heat | In order to fuel and heat the TJ-II plasma, the following systems are used: | ||
* [[Electron Cyclotron Resonant Heating]] ( | * [[TJ-II:Gas puff|Gas puff]] | ||
* [[Neutral Beam Injection]] (NBI | * [[TJ-II:Electron Cyclotron Resonant Heating|Electron Cyclotron Resonant Heating]] (ECRH) | ||
* [[TJ-II:Neutral Beam Injection|Neutral Beam Injection]] (NBI) | |||
* [[TJ-II:Electron Bernstein Wave Heating|Electron Bernstein Wave Heating]] (EBWH) | |||
* [[TJ-II:Pellet injector|Pellet injector]] (PI) | |||
== Control and data acquisition == | == Control and data acquisition == | ||
The [[ | The [[TJ-II:Control and data acquisition systems|Control and data acquisition systems]] were designed end developed at CIEMAT. | ||
== Diagnostics == | == Diagnostics == | ||
TJ-II is fitted with an extensive set of diagnostic systems: | [[File:TJ-II_top_view.jpg|400px|thumb|right|TJ-II in 2012; front left: [[TJ-II:Thomson Scattering|Thomson Scattering]]; left and bottom right: [[TJ-II:Neutral Beam Injection|NBI]]; top: the inclined structures are two [[TJ-II:Heavy Ion Beam Probe|HIBP]] systems. Also visible on top, up front, is the reciprocating [[TJ-II:Langmuir Probes|Langmuir Probe]].]] | ||
* [[ | TJ-II is fitted with an extensive set of diagnostic systems installed in its 96 access [[TJ-II:Ports|ports]]. For information on the magnetic coordinate system (required for cross-diagnostic comparisons), see [[TJ-II:Magnetic_coordinates|TJ-II magnetic coordinates]]. | ||
* [[ | |||
* [[Electron Cyclotron Emission]] | ''Passive diagnostics'' | ||
* [[Soft X- | * [[TJ-II:Magnetics|Magnetics]] | ||
* [[Bolometry]] | * [[TJ-II:Halpha monitors|Halpha monitors]] | ||
* [[Heavy Ion Beam Probe]] | * [[TJ-II:Electron Cyclotron Emission|Electron Cyclotron Emission]] | ||
* [[Langmuir Probes]] | * [[TJ-II:Soft X-rays|Soft X-rays]] | ||
* [[ | * [[TJ-II:Multifilter electron temperature diagnostic|Multifilter electron temperature diagnostic]] | ||
* [[ | * [[TJ-II:Bolometry|Bolometry]] | ||
* [[ | * [[TJ-II:Spectroscopy|Spectroscopy]] | ||
* [[ | * [[TJ-II:Charge exchange spectroscopy|Charge exchange spectroscopy]] | ||
* [[TJ-II:Compact Neutral Particle Analyzer|Compact Neutral Particle Analyzer]] | |||
* [[TJ-II:Fast ion loss probe|Fast ion loss probe]] | |||
* [[TJ-II:Retarding Field Analyzer|Retarding Field Analyzer]] | |||
* [[TJ-II:Fast camera|Fast camera]] | |||
''Active diagnostics'' | |||
* [[TJ-II:Interferometry|Interferometry]] | |||
* [[TJ-II:Reflectometry|Reflectometry]] | |||
* [[TJ-II:Heavy Ion Beam Probe|Heavy Ion Beam Probe]] | |||
* [[TJ-II:Langmuir Probes|Langmuir Probes]] | |||
* [[TJ-II:Thomson Scattering|Thomson Scattering]] | |||
* [[TJ-II:Diagnostic neutral beam|Diagnostic neutral beam]] | |||
* [[TJ-II:Helium Beam|Helium Beam]] | |||
* [[TJ-II:Lithium Beam|Lithium Beam]] | |||
[https://info.fusion.ciemat.es/cgi-bin/TJII_data.cgi Interactive on-line data visualization] | |||
== Numerical resources == | |||
=== Simulation codes === | |||
* [[VMEC]] - 3D Plasma equilibrium, assuming nested flux surfaces | |||
* [[PIES]] - 3D Plasma equilibrium | |||
* [[HL]] - Field line following code | |||
* [[ASTRA]] - Plasma transport | |||
* [[PROCTR]] - Plasma transport | |||
* [[EUTERPE]] - Gyrokinetic code | |||
* [[EIRENE]] - A Monte Carlo neutral gas transport code | |||
* [[FAFNER]] | |||
* [[CUTIE]] - Full-tokamak fluid turbulence | |||
* [[MOCA]] - Monte Carlo [[Neoclassical transport]] code | |||
* [[DKES]] - [[Neoclassical transport]] code | |||
* [[KNOSOS]] - [[Neoclassical transport]] code | |||
* [[TRECE]] - Microwave ray tracing | |||
* [[TRUBA]]- Microwave beam/ray tracing including electron Bernstein wave calculations. | |||
=== Data analysis === | |||
* [[Wave_ana]] - Linear and non-linear data analysis, spectral analysis using Fourier and Wavelets | |||
* [[EBITA]] - Tomographic reconstruction | |||
* [[TJ-II:Tomography|Tomography]] - Tomographic reconstruction based on mode decomposition in flux surface geometry | |||
=== Software tools === | |||
* [[MDSplus]] | |||
== | == References == | ||
<references /> | |||
[[Category:Toroidal confinement devices]] | |||
Latest revision as of 15:49, 24 May 2024
TJ-II is a flexible Heliac installed at Spain's National Fusion Laboratory. It is one of Spain's Unique Scientific and Technical Infrastructures. It is currently operational.
History
The flexible Heliac TJ-II was designed on the basis of calculations performed by the team of physicists and engineers of CIEMAT, in collaboration with the Oak Ridge National Laboratory (ORNL, USA) and the Institut für PlasmaPhysik at Garching (IPP, Germany). [1], [2]. The TJ-II project received preferential support from Euratom for phase I (Physics) in 1986[3] and for phase II (Engineering) in 1990[4]. The construction of this flexible Heliac was carried out in parts according to its constitutive elements, which were commissioned to various European companies, although 60% of the investments reverted back to Spanish companies.
The first plasma was produced in 1997.[5]
Precedents
TJ-II is the third magnetic confinement device in a series. In 1983, the device TJ-I was taken into operation. The denomination of this device is due to the abbreviation of "Tokamak de la Junta de Energía Nuclear", this being the former denomination of CIEMAT. The abbreviation was maintained for successive devices for administrative reasons.
In 1994, the torsatron TJ-IU was taken into operation. This was the first magnetic confinement device entirely built in Spain. Currently, TJ-IU is located at the University of Stuttgart in Germany under the name of TJ-K (the 'K' stands for Kiel, its first location in Germany, before arriving in Stuttgart).
Description
In TJ-II, the magnetic trap is obtained by means of various sets of coils that completely determine the magnetic surfaces before plasma initiation. The toroidal field is created by 32 coils. The three-dimensional twist of the central axis of the configuration is generated by means of two central coils: one circular and one helical. The horizontal position of the plasma is controlled by the vertical field coils. The combined action of these magnetic fields generate bean-shaped magnetic surfaces that guide the particles of the plasma so that they do not collide with the vacuum vessel wall.
TJ-II discharges last around 0.25 s, with a repetition frequency of about 7 minutes.
| Parameter | Value | Unit |
|---|---|---|
| Major radius, R0: | 1.5 | m |
| Minor radius, a: | < 0.22 | m |
| Plasma volume, V: | 1 | m3 |
| Field periods: | 4 | |
| TF coils: | 32 | |
| Number of ports: | 104 | |
| Rotational transform, ι/2π: | 0.9 - 2.5 | |
| Magnetic field on axis, B0: | ~1 | T |
| ECRH heating power, PECRH: | < 600 | kW |
| NBI heating power, PNBI: | < 2 | MW |
| Pulse length: | < 200 | ms |
Goals and Research
The objective of the experimental program of TJ-II is to investigate the physics of a device with a helical magnetic axis having a great flexibility in its magnetic configuration, and to contribute to the international effort regarding the study of magnetic confinement devices for fusion.
Also refer to LNF:Plasma Physics.
Operation
- A vacuum system controls the pressure inside the vacuum vessel.
- The electric energy required for a TJ-II discharge is obtained from a flywheel generator.
- The coils are cooled by means of a cooling system.
- An extensive set of systems is available to perform plasma wall conditioning.
- Two movable limiters can be used to limit the plasma.
- A biasing probe can be used to apply a bias potential at the edge.
- A mechanical paddle is used to suppress runaway electrons during current ramp-up and ramp-down.
Heating and fuelling
In order to fuel and heat the TJ-II plasma, the following systems are used:
- Gas puff
- Electron Cyclotron Resonant Heating (ECRH)
- Neutral Beam Injection (NBI)
- Electron Bernstein Wave Heating (EBWH)
- Pellet injector (PI)
Control and data acquisition
The Control and data acquisition systems were designed end developed at CIEMAT.
Diagnostics
TJ-II in 2012; front left: Thomson Scattering; left and bottom right: NBI; top: the inclined structures are two HIBP systems. Also visible on top, up front, is the reciprocating Langmuir Probe.
TJ-II is fitted with an extensive set of diagnostic systems installed in its 96 access ports. For information on the magnetic coordinate system (required for cross-diagnostic comparisons), see TJ-II magnetic coordinates.
Passive diagnostics
- Magnetics
- Halpha monitors
- Electron Cyclotron Emission
- Soft X-rays
- Multifilter electron temperature diagnostic
- Bolometry
- Spectroscopy
- Charge exchange spectroscopy
- Compact Neutral Particle Analyzer
- Fast ion loss probe
- Retarding Field Analyzer
- Fast camera
Active diagnostics
- Interferometry
- Reflectometry
- Heavy Ion Beam Probe
- Langmuir Probes
- Thomson Scattering
- Diagnostic neutral beam
- Helium Beam
- Lithium Beam
Interactive on-line data visualization
Numerical resources
Simulation codes
- VMEC - 3D Plasma equilibrium, assuming nested flux surfaces
- PIES - 3D Plasma equilibrium
- HL - Field line following code
- ASTRA - Plasma transport
- PROCTR - Plasma transport
- EUTERPE - Gyrokinetic code
- EIRENE - A Monte Carlo neutral gas transport code
- FAFNER
- CUTIE - Full-tokamak fluid turbulence
- MOCA - Monte Carlo Neoclassical transport code
- DKES - Neoclassical transport code
- KNOSOS - Neoclassical transport code
- TRECE - Microwave ray tracing
- TRUBA- Microwave beam/ray tracing including electron Bernstein wave calculations.
Data analysis
- Wave_ana - Linear and non-linear data analysis, spectral analysis using Fourier and Wavelets
- EBITA - Tomographic reconstruction
- Tomography - Tomographic reconstruction based on mode decomposition in flux surface geometry
Software tools
References
- ↑ T.C. Hender et al, Studies of a flexible heliac configuration, Report ORNL/TM-10374 (1987) OSTI ID: 6007697
- ↑ A. Perea et al., "Physics Issues in the Design of TJ-II, Proc. 12th European Conf. Controlled Fusion and Plasma Physics, Budapest, Hungary, 1985, ECA Vol. 9F, Part I, p. 433, European Physical Society (1985)
- ↑ Application for EURATOM preferential support (Phase I) - TJ-II EXPERIMENT, Technical report, Asociación EURATOM/CIEMAT, 1985
- ↑ Application for EURATOM preferential support (Phase II) - TJ-II EXPERIMENT, Technical report, Asociación EURATOM/CIEMAT, 1989
- ↑ Special issue of CIEMAT's magazine Vertices commemorating 20 years of experiments (December, 2017)