A dual heavy ion beam probe diagnostic on the TJ-II stellarator
The aim of the report is to show the development of HIBP diagnostics on the TJ-II stellarator and, as a result, the expansion of the range of plasma parameters measurements. The first Heavy Ion Beam Probe (HIBP-1) diagnostic is being used on TJ-II stellarator since 2000. It has been shown significan...
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| Zitieren: | A dual heavy ion beam probe diagnostic on the TJ-II stellarator / O.O. Chmyga, E. Ascasibar, J. Barcala, M.A. Drabinskiy, L.G. Eliseev, C. Hidalgo, P.O. Khabanov, S.M. Khrebtov, O.D. Komarov, O.S. Kozachok, L.I. Krupnik, S.E. Lysenko, A.V. Melnikov, A. Molinero, J.L.de Pablos, S.V. Perfilov, V.N. Zenin, TJ-II Team // Problems of atomic science and technology. — 2019. — № 1. — С. 248-251. — Бібліогр.: 12 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1949032025-02-09T14:21:48Z A dual heavy ion beam probe diagnostic on the TJ-II stellarator Подвійна діагностика зондування плазми пучком важких іонів на стелараторі TJ-II Двойная диагностика зондирования плазмы пучком тяжелых ионов на стеллараторе TJ-II Chmyga, O.O. Ascasibar, E. Barcala, J. Drabinskiy, M.A. Eliseev, L.G. Hidalgo, C. Khabanov, P.O. Khrebtov, S.M. Komarov, O.D. Kozachok, O.S. Krupnik, L.I. Lysenko, S.E. Melnikov, A.V. Molinero, A. Pablos, J.L.de Perfilov, S.V. Zenin, V.N. TJ-II Team Plasma diagnostics The aim of the report is to show the development of HIBP diagnostics on the TJ-II stellarator and, as a result, the expansion of the range of plasma parameters measurements. The first Heavy Ion Beam Probe (HIBP-1) diagnostic is being used on TJ-II stellarator since 2000. It has been shown significant progress in the measurements of plasma profiles and oscillations. The second HIBP-2 system was installed on TJ-II in 2012. Dual HIBP system, consisting of two identical HIBP-1 and HIBP-2 located ¼ torus apart, provides the measurement of the long-range correlations of plasma parameters in the full plasma column. Low noise high gain (10⁷ V/A) preamplifiers with 1 Hz bandwidth sampling is used. They allow to study broadband turbulence and quasi-coherent modes like geodesic acoustic modes, Alfven eigenmodes, suprathermal electron induced modes, etc. New capabilities of the dual HIBP diagnostic in plasma potential and density investigations were demonstrated on TJ-II stellarator in the measurements of the correlation between fluctuations in different poloidal and toroidal locations: on the same field line, on the same magnetic surface or on different magnetic surfaces at different points, separated toroidally and/or poloidally. На стелараторі TJ-II створена подвійна система зондування плазми пучком важких іонів (ЗППВІ). Система складається з двох ідентичних комплексів, розташованих на відстані ¼ тора. Перший діагностичний комплекс почав діяти в 2000 році. Другий комплекс був встановлений в 2012 році. Використання підсилювачів детекторних сигналів з низьким рівнем шуму (10⁷ В/A) з пропускною здатністю 1 МГц дозволяє вивчати широкосмугову турбулентність та квазікогерентні режими, такі як геодезичні акустичні моди; альфвенівські моди; супертермальні моди, які збурюються швидкими електронами, тощо. Нові можливості подвійної системи були продемонстровані при вимірюваннях далеких кореляцій між флуктуаціями в різних полоїдальних та тороїдальних місцях: на одній лінії магнітного поля, на одній або на різних магнітних поверхнях у різних точках, розташованих тороїдально та/або полоїдально. На стеллараторе TJ-II создана двойная система зондирования плазмы пучком тяжелых ионов (ЗППТИ). Система состоит из двух идентичных комплексов, расположенных на расстоянии ¼ тора. Первый диагностический комплекс начал действовать в 2000 году. Второй комплекс был установлен в 2012 году. Использование усилителей детекторных сигналов с низким уровнем шума (10⁷ В/A) и полосой пропускания 1 МГц позволяет изучать широкополосную урбулентность и квазикогерентные моды, такие как геодезические акустические моды; альфвеновские собственные моды; моды, индуцированные надтепловыми электронами и т.д. Новые возможности двойной системы были продемонстрированы при измерениях дальних корреляций между флуктуациями, измеренными в различных полоидальних и тороидальных положениях: на одной или на разных магнитных поверхностях, в различных точках, смещенных тороидально и/или полоидально. The work of Kharkiv team was carried out by STCU, Project P-507F. The work of Kurchatov team was funded by Russian Science Foundation (project 14-22-00193). A.V. Melnikov was partly supported by the Competitiveness Program of NRNU MEPhI. 2019 Article A dual heavy ion beam probe diagnostic on the TJ-II stellarator / O.O. Chmyga, E. Ascasibar, J. Barcala, M.A. Drabinskiy, L.G. Eliseev, C. Hidalgo, P.O. Khabanov, S.M. Khrebtov, O.D. Komarov, O.S. Kozachok, L.I. Krupnik, S.E. Lysenko, A.V. Melnikov, A. Molinero, J.L.de Pablos, S.V. Perfilov, V.N. Zenin, TJ-II Team // Problems of atomic science and technology. — 2019. — № 1. — С. 248-251. — Бібліогр.: 12 назв. — англ. 1562-6016 PACS: 52.70.Nc https://nasplib.isofts.kiev.ua/handle/123456789/194903 en Вопросы атомной науки и техники application/pdf Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
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| topic |
Plasma diagnostics Plasma diagnostics |
| spellingShingle |
Plasma diagnostics Plasma diagnostics Chmyga, O.O. Ascasibar, E. Barcala, J. Drabinskiy, M.A. Eliseev, L.G. Hidalgo, C. Khabanov, P.O. Khrebtov, S.M. Komarov, O.D. Kozachok, O.S. Krupnik, L.I. Lysenko, S.E. Melnikov, A.V. Molinero, A. Pablos, J.L.de Perfilov, S.V. Zenin, V.N. TJ-II Team A dual heavy ion beam probe diagnostic on the TJ-II stellarator Вопросы атомной науки и техники |
| description |
The aim of the report is to show the development of HIBP diagnostics on the TJ-II stellarator and, as a result, the expansion of the range of plasma parameters measurements. The first Heavy Ion Beam Probe (HIBP-1) diagnostic is being used on TJ-II stellarator since 2000. It has been shown significant progress in the measurements of plasma profiles and oscillations. The second HIBP-2 system was installed on TJ-II in 2012. Dual HIBP system, consisting of two identical HIBP-1 and HIBP-2 located ¼ torus apart, provides the measurement of the long-range correlations of plasma parameters in the full plasma column. Low noise high gain (10⁷ V/A) preamplifiers with 1 Hz bandwidth sampling is used. They allow to study broadband turbulence and quasi-coherent modes like geodesic acoustic modes, Alfven eigenmodes, suprathermal electron induced modes, etc. New capabilities of the dual HIBP diagnostic in plasma potential and density investigations were demonstrated on TJ-II stellarator in the measurements of the correlation between fluctuations in different poloidal and toroidal locations: on the same field line, on the same magnetic surface or on different magnetic surfaces at different points, separated toroidally and/or poloidally. |
| format |
Article |
| author |
Chmyga, O.O. Ascasibar, E. Barcala, J. Drabinskiy, M.A. Eliseev, L.G. Hidalgo, C. Khabanov, P.O. Khrebtov, S.M. Komarov, O.D. Kozachok, O.S. Krupnik, L.I. Lysenko, S.E. Melnikov, A.V. Molinero, A. Pablos, J.L.de Perfilov, S.V. Zenin, V.N. TJ-II Team |
| author_facet |
Chmyga, O.O. Ascasibar, E. Barcala, J. Drabinskiy, M.A. Eliseev, L.G. Hidalgo, C. Khabanov, P.O. Khrebtov, S.M. Komarov, O.D. Kozachok, O.S. Krupnik, L.I. Lysenko, S.E. Melnikov, A.V. Molinero, A. Pablos, J.L.de Perfilov, S.V. Zenin, V.N. TJ-II Team |
| author_sort |
Chmyga, O.O. |
| title |
A dual heavy ion beam probe diagnostic on the TJ-II stellarator |
| title_short |
A dual heavy ion beam probe diagnostic on the TJ-II stellarator |
| title_full |
A dual heavy ion beam probe diagnostic on the TJ-II stellarator |
| title_fullStr |
A dual heavy ion beam probe diagnostic on the TJ-II stellarator |
| title_full_unstemmed |
A dual heavy ion beam probe diagnostic on the TJ-II stellarator |
| title_sort |
dual heavy ion beam probe diagnostic on the tj-ii stellarator |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2019 |
| topic_facet |
Plasma diagnostics |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/194903 |
| citation_txt |
A dual heavy ion beam probe diagnostic on the TJ-II stellarator / O.O. Chmyga, E. Ascasibar, J. Barcala, M.A. Drabinskiy, L.G. Eliseev, C. Hidalgo, P.O. Khabanov, S.M. Khrebtov, O.D. Komarov, O.S. Kozachok, L.I. Krupnik, S.E. Lysenko, A.V. Melnikov, A. Molinero, J.L.de Pablos, S.V. Perfilov, V.N. Zenin, TJ-II Team // Problems of atomic science and technology. — 2019. — № 1. — С. 248-251. — Бібліогр.: 12 назв. — англ. |
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Вопросы атомной науки и техники |
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ISSN 1562-6016. ВАНТ. 2019. №1(119)
248 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2019, № 1. Series: Plasma Physics (25), p. 248-251.
A DUAL HEAVY ION BEAM PROBE DIAGNOSTIC ON THE TJ-II
STELLARATOR
O.O. Chmyga
1
, E. Ascasibar
2
, J. Barcala
2
, M.A. Drabinskiy
3
, L.G. Eliseev
3
, C. Hidalgo
2
,
P.O. Khabanov
3
, S.M. Khrebtov
1
, O.D. Komarov
1
, O.S. Kozachok
1
, L.I. Krupnik
1
,
S.E. Lysenko
1
, A.V. Melnikov
3,4
, A. Molinero
2
, J.L. de Pablos
2
, S.V. Perfilov
3
,
V.N. Zenin
3
, and TJ-II Team
1
National Science Center “Kharkov Institute of Physics and Technology”,
Institute of Plasma Physics, Kharkiv, Ukraine;
2
Fusion National Laboratory, CIEMAT, Madrid, Spain;
3
National Research Centre “Kurchatov Institute, Moscow, Russia;
4
National Research Nuclear University MEPhI, Moscow, Russia
The aim of the report is to show the development of HIBP diagnostics on the TJ-II stellarator and, as a result, the
expansion of the range of plasma parameters measurements. The first Heavy Ion Beam Probe (HIBP-1) diagnostic is
being used on TJ-II stellarator since 2000. It has been shown significant progress in the measurements of plasma
profiles and oscillations. The second HIBP-2 system was installed on TJ-II in 2012. Dual HIBP system, consisting
of two identical HIBP-1 and HIBP-2 located ¼ torus apart, provides the measurement of the long-range correlations
of plasma parameters in the full plasma column. Low noise high gain (10
7
V/A) preamplifiers with 1 MHz
bandwidth sampling is used. They allow to study broadband turbulence and quasi-coherent modes like geodesic
acoustic modes, Alfven eigenmodes, suprathermal electron induced modes, etc. New capabilities of the dual HIBP
diagnostic in plasma potential and density investigations were demonstrated on TJ-II stellarator in the measurements
of the correlation between fluctuations in different poloidal and toroidal locations: on the same field line, on the
same magnetic surface or on different magnetic surfaces at different points, separated toroidally and/or poloidally.
PACS: 52.70.Nc
INTRODUCTION
The first plasma in TJ-II stellarator was produced in
1997. The locations of main diagnostics and parameters
are shown in Fig. 1 and Table 1.
Fig. 1. Schematic view of TJ-II stellarator with
the locations of dual HIBP diagnostic
HIBP-1 diagnostic was installed in 2000 [1, 2] and
had the following parameters: injector primary cesium
ion current 30…60 A, energy analyzer – 1 slit/4
collectors, amplifier frequency bandwidth 125 kHz.
The initial HIBP-2 parameters (2012 year) were:
injector primary ion current 50…100 A, energy
analyzer 5 slit/20 collectors, preamplifier frequency
bandwidth 500 kHz [3].
Both HIBP-1 and HIBP-2 of dual HIBP operate in
the similar cross-section of TJ-II vacuum chamber,
located 90 degrees toroidally apart (see Fig. 1). Distance
between measurement points of the diagnostics in
toroidal direction is 2...3 m. The main HIBP parameters
are shown in Table 2 for injectors and Table 3 for
analyzers.
HIBP-2 diagnostic differs from HIBP-1. It has 2
energy analyzers contrasting to one analyzer in HIBP-1
[4].
Each analyzer of HIBP-2 has 5 entrance slits (20
channels of simultaneous measurements), HIBP-1 has 2
entrance slits (8 channels).
Table 1
Main parameters of the stellarator TJ-II
Parameter Value Unit
Major radius, R0 1.5 m
Minor radius, a ‹ 0.22 m
Plasma volume, V 1 m
3
Field periods 4 –
TF coils 32 –
Numbers of ports 104 –
Rotational transform, l/2π 0.9…2.5 –
Magnetic field on axis, B0 1 T
ECRH heating power, PECRH ‹ 600 kW
NBI heating power, PNBI ‹ 1 MW
Density, ne ‹ 6 10
19
m
−3
Pulse length ‹ 300 ms
ISSN 1562-6016. ВАНТ. 2019. №1(119) 249
Fig. 2. Schematic of Dual HIBP and measurement
points position (radial scan) in plasma with the
standard TJ-II magnetic configuration
Table 2
Parameters of injectors: primary ion current Ipc,
Faraday cup diameter internal Ø FC, distance between
deflecting plates lDP
Injector Ipc, A Ø FC, mm lDP, mm
HIBP-1 30…200 26 25
HIBP-2 30…350 50 35
Table 3
Parameters of analyzers
Analyzer №
analyzers
Slits/
channels
Amplifier
location
Ubeam /Uan,
kV
HIBP-1 1 2/8 external 127/23.55
HIBP-2 2 2·5/20 internal 132/22.65
1. HIBP DIAGNOSTICS OPTIMIZATION
The large-scale modernization of dual HIBP
diagnostic was recently completed. Modernization was
carried out in the following areas:
– injectors – upgrade of the emitter block design
and, emitter manufacturing technology;
– energy analyzers – installation of two entrance
slits (8 measurement channels) on HIBP-1, adjustment
of analyzer 2 on HIBP-2 (5 slits, 20 channels), upgrade
of amplifiers for HIBP-1 and HIBP-2 analyzers (1 MHz
bandwidth and 10
7
V/A gain
);
– software – upgrade of the program for monitoring
and controlling parameters of dual HIBP.
This modernization allows to simplify the control
and monitoring of the system parameters, increase the
life-time of the solid-state cesium thermo-ionic emitter.
Increase in the primary ion current (up to 200 μA for
HIBP-1 and up to 350 μA for HIBP-2) allows to
improve the signal-to-noise ratio at the periphery and at
the center of the plasma (at a density up to 3·10
19
m
-3
).
2. EXPERIMENTAL RESULTS
HIBP-1 and HIBP-2 (Fig. 2) may operate separately
or jointly (simultaneously). Simultaneous operation of
both HIBPs is aimed to study the long-range correlation
(LRC) of the oscillations of the core plasma electrostatic
potential, density and poloidal magnetic field, and so
directed to the study of Alfvén eigenmodes (AE) and
zonal flows in toroidal plasmas.
2.1. LONG-RANGE PLASMA POTENTIAL
CORRELATION
Long-range plasma potential correlations present a
fingerprint of the plasma behavior during the development
of edge shear flows and the key role of electric fields to
amplify them.
Fig. 3. Spectrogram of the coherence between potential
signals, Phi1 detected by HIBP-1
and Phi2 detected by HIBP-2.
Bursts of coherency between potentials at the
coincidence of SV radial positions for both beams
evidence to LRCs of potential, localized
at the certain radius (a);
HIBP-1 scans over the Low-field-side of the plasma
cross section,
HIBP-2 in the fixed position (b); variation of total
beam current (plasma density) during radial scan (c)
Results (Figs. 3-5)show the presence of the long-
range correlations in potential fluctuations, which are
amplified by the development of radial electric fields
during ECRH, whereas there is no correlation between
ion saturation current signals [5, 6].
2.2. ALFVEN EIGENMODES
(fAE ~ 100…300 kHz)
Spatial distribution of AEs was studied by dual
HIBP in the plasma core [7, 8]. Spectrogram of the
coherence between potential signals is shown on Fig. 6.
250 ISSN 1562-6016. ВАНТ. 2019. №1(119)
Fig. 4. LRCs in the plasma potential averaged over
0<f< 20 kHz measured with HIBP-1 in the scanning
mode and HIBP-2 at the fixed point rho=-0.63 (shot
#39894) are significantly increase when ECRH is
applied
Fig. 5. LRCs averaged over 0<f< 20 kHz in the
secondary beam total current (which is proportional to
the plasma density) are in the order of the noise level in
all heating scenarios
Fig. 6. Spectrogram of the coherence between potential
signals, Phi1 detected by HIBP-1 and Phi2 detected by
HIBP-2, both scan over the plasma cross section (a).
Plasma potentials during NBI and NBI+ECRH (b)
2.2. INFLUENCE OF PELLETS ON PLASMA
POTENTIAL AND FLUCTUATION LEVELS
The influence of pellets on core plasma turbulence
and plasma profiles has been recently investigated using
the dual HIBP. Experiments (Fig. 7) show the change in
plasma potential (transition from ion to electron root of
the ambipolarity equation) [9, 10]. Density fluctuations
is strongly reduced in a short time scale (1 ms),
followed by an increase along the evolution of plasma
density and the recovery of the electron temperature
[11].
Fig. 7. Influence of pellets on plasma potential and
fluctuation levels
CONCLUSIONS
HIBP is a unique diagnostic to study directly plasma
electric potential and turbulence characteristics in
toroidal plasmas. The dual HIBP diagnostic is the next
level of development of this diagnostic, which allows to
measure long-range correlations in plasma potential and
density, toroidal and poloidal structure of plasma
turbulence and instability modes in the core and edge
plasmas. Development of this diagnostic on TJ-II
stellarator opens unique possibilities in this field, which
is the most interesting and fast growing branch of both
fundamental and applied physics of the magnetically
confined plasma [12]. At present, dual HIBP is involved
in all pilot physical programs of TJ-II: Zonal Flow, L-H
transitions, ELMs characteristics, Alfven modes, MHD-
activity, pellets experiment, etc. Next steps of
optimization will be an upgrade of the HIBP-1 primary
beam-line to increase ion current to the level of the
HIBP-2, installation of focusing power supplies on dual
HIBP diagnostic to optimize the focusing process of the
primary ion beams, modify the HIBP-1 analyzer –
5 slits/20 channels.
ACKNOWLEDGEMENTS
The work of Kharkiv team was carried out by STCU,
Project P-507F. The work of Kurchatov team was
funded by Russian Science Foundation (project 14-22-
00193). A.V. Melnikov was partly supported by the
Competitiveness Program of NRNU MEPhI.
ISSN 1562-6016. ВАНТ. 2019. №1(119) 251
REFERENCES
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Article received 15.12.2018
ДВОЙНАЯ ДИАГНОСТИКА ЗОНДИРОВАНИЯ ПЛАЗМЫ ПУЧКОМ ТЯЖЕЛЫХ ИОНОВ
НА СТЕЛЛАРАТОРЕ TJ-II
А.А. Чмыга, E. Ascasibar, J. Barcala, М.А. Драбинский, Л.Г. Елисеев, C. Hidalgo, П.О. Хабанов,
С.М. Хребтов, А.Д. Комаров, А.С. Козачек, Л.И. Крупник, С.Е. Лысенко, А.В. Мельников, A. Molinero,
J.L. de Pablos, С.В. Перфилов, В.Н. Зенин и TJ-II группа
На стеллараторе TJ-II создана двойная система зондирования плазмы пучком тяжелых ионов (ЗППТИ).
Система состоит из двух идентичных комплексов, расположенных на расстоянии ¼ тора. Первый
диагностический комплекс начал действовать в 2000 году. Второй комплекс был установлен в 2012 году.
Использование усилителей детекторных сигналов с низким уровнем шума (10
7
В/A) и полосой пропускания
1 МГц позволяет изучать широкополосную турбулентность и квазикогерентные моды, такие как
геодезические акустические моды; альфвеновские собственные моды; моды, индуцированные
надтепловыми электронами и т. д. Новые возможности двойной системы были продемонстрированы при
измерениях дальних корреляций между флуктуациями, измеренными в различных полоидальних и
тороидальных положениях: на одной или на разных магнитных поверхностях, в различных точках,
смещенных тороидально и/или полоидально.
ПОДВІЙНА ДІАГНОСТИКА ЗОНДУВАННЯ ПЛАЗМИ ПУЧКОМ ВАЖКИХ ІОНІВ
НА СТЕЛАРАТОРІ TJ-II
О.О. Чмига, E. Ascasibar, J. Barcala, М.А. Драбинський, Л.Г. Елісеєв, C. Hidalgo, П.О. Хабанов,
С.М. Хребтов, О.Д. Комаров, О.С. Козачок, Л.І. Крупнік, С.Є. Лисенко, А.В. Мельніков, A. Molinero,
J.L. de Pablos, С.В. Перфілов, В.Н. Зенін та TJ-II група
На стелараторі TJ-II створена подвійна система зондування плазми пучком важких іонів (ЗППВІ).
Система складається з двох ідентичних комплексів, розташованих на відстані ¼ тора. Перший
діагностичний комплекс почав діяти в 2000 році. Другий комплекс був встановлений в 2012 році.
Використання підсилювачів детекторних сигналів з низьким рівнем шуму (10
7
В/A) з пропускною здатністю
1 МГц дозволяє вивчати широкосмугову турбулентність та квазікогерентні режими, такі як геодезичні
акустичні моди; альфвенівські моди; супертермальні моди, які збурюються швидкими електронами, тощо.
Нові можливості подвійної системи були продемонстровані при вимірюваннях далеких кореляцій між
флуктуаціями в різних полоїдальних та тороїдальних місцях: на одній лінії магнітного поля, на одній або на
різних магнітних поверхнях у різних точках, розташованих тороїдально та/або полоїдально.
http://iopscience.iop.org/journal/0029-5515
http://iopscience.iop.org/journal/0029-5515
http://iopscience.iop.org/volume/0029-5515/56
http://iopscience.iop.org/issue/0029-5515/56/7
http://iopscience.iop.org/journal/0029-5515
http://iopscience.iop.org/volume/0029-5515/56
http://iopscience.iop.org/issue/0029-5515/56/7
https://arxiv.org/search/physics?searchtype=author&query=Alonso%2C+J+A
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