TJ-II: Difference between revisions

From FusionWiki
Jump to navigation Jump to search
mNo edit summary
 
(85 intermediate revisions by 9 users not shown)
Line 1: Line 1:
TJ-II is a flexible Heliac installed at Spain's [[Laboratorio Nacional de Fusión|National Fusion Laboratory]]. It is currently operational.
[[File:TJII_model.jpg|500px|thumb|right|TJ-II Model]]


[[File:TJ-II_3D_perspective.jpg|300px|thumb|right|TJ-II perspective view]]
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 first plasma was produced in 1999.
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 [[Junta de Energía Nuclear]]", this being the former denomination of [[CIEMAT]]. The abbreviation was maintained for successive devices for administrative reasons.
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 [http://www.ipf.uni-stuttgart.de/index_e.html 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 ==


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 tree-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.  
[[File:TJ-II_3D_perspective.jpg|300px|thumb|right|TJ-II perspective view]]
 
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.
TJ-II discharges last around 0.25 s, with a repetition frequency of about 7 minutes.


== Goals ==
{| 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, ''&iota;/2&pi;'':          ||  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.
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.  


[[File:TJII_model.jpg|500px|thumb|center|TJ-II Model]]
Also refer to [[LNF:Plasma Physics]].


== Operation ==
== Operation ==


The electric energy required for a TJ-II discharge is obtained from a [[TJ-II:flywheel generator|flywheel generator]].
* A [[TJ-II:Vacuum system|vacuum system]] controls the pressure inside the vacuum vessel.
The coils are cooled by means of a [[TJ-II:cooling system|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 and fuelling ==
== Heating and fuelling ==


In order to heat and fuel the TJ-II plasma, the following heating systems are used:  
In order to fuel and heat the TJ-II plasma, the following systems are used:  
* [[TJ-II:Electron Cyclotron Resonant Heating|Electron Cyclotron Resonant Heating]] (ECH, 2 injection beamlines, 600 kW)
* [[TJ-II:Neutral Beam Injection|Neutral Beam Injection]] (NBI, two injectors, up to 4 MW)
* [[TJ-II:Gas puff|Gas puff]]
* [[TJ-II:Gas puff|Gas puff]]
* [[TJ-II:Pellet injector|Pellet injector]]
* [[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 ==
Line 47: Line 88:
== Diagnostics ==
== Diagnostics ==


TJ-II is fitted with an extensive set of diagnostic systems. For information on their physical location, see  
[[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:Sectors|TJ-II Sectors]].
 
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]].
 
''Passive diagnostics''
* [[TJ-II:Magnetics|Magnetics]]
* [[TJ-II:Halpha monitors|Halpha monitors]]
* [[TJ-II:Halpha monitors|Halpha monitors]]
* [[TJ-II:Mirnov coils|Mirnov coils]]
* [[TJ-II:Electron Cyclotron Emission|Electron Cyclotron Emission]]
* [[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:Interferometry|Interferometry]]
* [[TJ-II:Reflectometry|Reflectometry]]
* [[TJ-II:Reflectometry|Reflectometry]]
* [[TJ-II:Electron Cyclotron Emission|Electron Cyclotron Emission]]
* [[TJ-II:Soft X-ray Tomography|Soft X-ray Tomography]]
* [[TJ-II:Bolometry|Bolometry]]
* [[TJ-II:Heavy Ion Beam Probe|Heavy Ion Beam Probe]]
* [[TJ-II:Heavy Ion Beam Probe|Heavy Ion Beam Probe]]
* [[TJ-II:Langmuir Probes|Langmuir Probes]]
* [[TJ-II:Langmuir Probes|Langmuir Probes]]
* [[TJ-II:Spectroscopy|Spectroscopy]]
* [[TJ-II:Charge exchange spectroscopy|Charge exchange spectroscopy]]
* [[TJ-II:Thomson Scattering|Thomson Scattering]]
* [[TJ-II:Thomson Scattering|Thomson Scattering]]
* [[TJ-II:Diagnostic neutral beam|Diagnostic neutral beam]]
* [[TJ-II:Helium Beam|Helium Beam]]
* [[TJ-II:Helium Beam|Helium Beam]]
* [[TJ-II:Fast camera|Fast camera]]
* [[TJ-II:Lithium Beam|Lithium Beam]]
 
[https://info.fusion.ciemat.es/cgi-bin/TJII_data.cgi Interactive on-line data visualization]


== Numerical resources ==
== Numerical resources ==
Line 69: Line 123:
* [[VMEC]] - 3D Plasma equilibrium, assuming nested flux surfaces
* [[VMEC]] - 3D Plasma equilibrium, assuming nested flux surfaces
* [[PIES]] - 3D Plasma equilibrium
* [[PIES]] - 3D Plasma equilibrium
* [[HL]] - Field line following code
* [[ASTRA]] - Plasma transport
* [[ASTRA]] - Plasma transport
* [[PROCTR]] - Plasma transport
* [[PROCTR]] - Plasma transport
* [[EIRENE]]
* [[EUTERPE]] - Gyrokinetic code
* [[EIRENE]] - A Monte Carlo neutral gas transport code
* [[FAFNER]]
* [[FAFNER]]
* [[CUTIE]] - Full-tokamak fluid turbulence
* [[CUTIE]] - Full-tokamak fluid turbulence
* [[MOCA]] - Monte Carlo Neoclassical transport code
* [[MOCA]] - Monte Carlo [[Neoclassical transport]] code
* [[Master]] - 1D Master Equation solver for non-diffusive transport
* [[DKES]] - [[Neoclassical transport]] code
* [[KNOSOS]] - [[Neoclassical transport]] code
* [[TRECE]] - Microwave ray tracing
* [[TRUBA]]- Microwave beam/ray tracing including electron Bernstein wave calculations.


=== Data analysis ===
=== Data analysis ===
* [[Wave_ana]] - Linear and non-linear data analysis, spectral analysis using Fourier and Wavelets
* [[Wave_ana]] - Linear and non-linear data analysis, spectral analysis using Fourier and Wavelets
* [[EBITA]] - Tomographic reconstruction
* [[EBITA]] - Tomographic reconstruction
* [[TJII:Tomography|Tomography]] - Tomographic reconstruction based on mode decomposition in flux surface geometry
* [[TJ-II:Tomography|Tomography]] - Tomographic reconstruction based on mode decomposition in flux surface geometry
* [[TJII:FM|FM]] - Density reconstruction for the reflectometer
 
=== Software tools ===
* [[MDSplus]]


== Research ==
== References ==
<references />


Some research topics at TJ-II are:
[[Category:Toroidal confinement devices]]
* [[TJ-II:Transport and the magnetic configuration|Transport and the magnetic configuration]]
* [[TJ-II:Confinement transitions|Confinement transitions]]
* [[TJ-II:Plasma Wall Interaction|Plasma Wall Interaction]]

Latest revision as of 15:49, 24 May 2024

TJ-II Model

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

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 (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

TJ-II perspective view

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

Heating and fuelling

In order to fuel and heat the TJ-II plasma, the following systems are used:

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

Active diagnostics

Interactive on-line data visualization

Numerical resources

Simulation codes

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

  1. T.C. Hender et al, Studies of a flexible heliac configuration, Report ORNL/TM-10374 (1987) OSTI ID: 6007697
  2. 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)
  3. Application for EURATOM preferential support (Phase I) - TJ-II EXPERIMENT, Technical report, Asociación EURATOM/CIEMAT, 1985
  4. Application for EURATOM preferential support (Phase II) - TJ-II EXPERIMENT, Technical report, Asociación EURATOM/CIEMAT, 1989
  5. Special issue of CIEMAT's magazine Vertices commemorating 20 years of experiments (December, 2017)