Author: J. Zajac | SZEPAPERS

Progress in diagnostics of the COMPASS tokamak

P. Bilkova P. Bohm O. Bogár E. Gauthier K. Kovarik J. P. Gunn D. I. Naydenkova A. Podolnik D. Réfy N. Vianello J. Adámek J. Horacek O. Grover R. Dejarnac J. Cavalier O. Ficker M. Hron M. Komm E. Matveeva R. Pánek M. Peterka J. Seidl M. Dimitrova D. Fridrich A. Devitre T. Markovic G. Anda D. Dunai M. Rabinski J. Stockel J. Mlynar R. Paprok K. Mitošinková M. Sos J. Varju M. Tomes M. Varavin P. Hacek J. Krbec R. Gomes M. Berta J. Havlicek A. Havranek T. Krizsanóczi V. Weinzettl P. Vondráček F. Zacek M. Vlainic M. Stano T. Pereira G. P. Ermak J. Zebrowski M. Jakubowski K. Malinowski M. Spolaore J. Zajac A. Silva S. Zoletnik Tsv Popov D. Sarychev M. Imrišek S. Nanobashvili

Publication Name: Journal of Instrumentation

Publication Date: 2017-12-07

Volume: 12

Issue: 12

Page Range: Unknown

Description:

The COMPASS tokamak at IPP Prague is a small-size device with an ITER-relevant plasma geometry and operating in both the Ohmic as well as neutral beam assisted H-modes since 2012. A basic set of diagnostics installed at the beginning of the COMPASS operation has been gradually broadened in type of diagnostics, extended in number of detectors and collected channels and improved by an increased data acquisition speed. In recent years, a significant progress in diagnostic development has been motivated by the improved COMPASS plasma performance and broadening of its scientific programme (L-H transition and pedestal scaling studies, magnetic perturbations, runaway electron control and mitigation, plasma-surface interaction and corresponding heat fluxes, Alfvenic and edge localized mode observations, disruptions, etc.). In this contribution, we describe major upgrades of a broad spectrum of the COMPASS diagnostics and discuss their potential for physical studies. In particular, scrape-off layer plasma diagnostics will be represented by a new concept for microsecond electron temperature and heat flux measurements - we introduce a new set of divertor Langmuir and ball-pen probe arrays, newly constructed probe heads for reciprocating manipulators as well as several types of standalone probes. Among optical tools, an upgraded high-resolution edge Thomson scattering diagnostic for pedestal studies and a set of new visible light and infrared (plasma-surface interaction investigations) cameras will be described. Particle and beam diagnostics will be covered by a neutral particle analyzer, diagnostics on a lithium beam, Cherenkov detectors (for a direct detection of runaway electrons) and neutron detectors. We also present new modifications of the microwave reflectometer for fast edge density profile measurements.

Open Access: Yes

DOI: 10.1088/1748-0221/12/12/C12015

Overview of the COMPASS diagnostics

P. Bilkova P. Bohm D. I. Naydenkova J. Adámek J. Horacek R. Dejarnac M. Hron R. Pánek I. Ďuran G. Anda J. Stockel J. Mlynar D. Sestak M. Aftanas G. Veres F. Janky J. Brotankova R. Melich P. Hacek R. Gomes M. Berta J. Havlicek V. Weinzettl F. Zacek A. Szappanos J. Zajac D. Jares J. Ghosh V. F. Shevchenko R. Scannell M. Walsh H. W. Müller V. Igochine A. Silva M. Manso S. Zoletnik Tsv Popov D. Sarychev V. K. Kiselov S. Nanobashvili

Publication Name: Fusion Engineering and Design

Publication Date: 2011-10-01

Volume: 86

Issue: 6-8

Page Range: 1227-1231

Description:

The COMPASS tokamak, a divertor device with clear H-mode and ITER-relevant geometry, has been re-installed in IPP Prague after its transport from CCFE in UK. The first plasma was achieved in December 2008. Many new diagnostic tools with both high temporal and spatial resolutions have been developed to address the scientific programme of COMPASS focused on H-mode physics and pedestal investigations. In the paper, an overview of existing and in near future planned diagnostics (magnetic, spectroscopy, microwave, probe and beam/particle) on COMPASS is given including their basic technical specifications and achievements. © 2011 EURATOM. Published by Elsevier B.V. All rights reserved.

Open Access: Yes

DOI: 10.1016/j.fusengdes.2010.12.024

Results of Joint Experiments and other IAEA activities on research using small tokamaks

N. Kirneva V. Vershkov M. Sokolov C. Silva D. Valcrcel R. Gonzales A. Fonseca B. Kuteev L. Petrov M. Kolokoltsov J. Herrera M. Nieto-Perez A. Czarnecka A. Talebitaher A. Melnikov P. Khorshid V. Soldatov C. R. Gutierrez Tapia R. Dejarnac P. Balan M. Hron H. Fernandes I. Ďuran D. Dunai J. Stockel J. Brotankova L. A. Berni E. Del Bosco J. Sentkerestiova M. Gryaznevich G. Van Oost E. Dufkova P. Peleman A. Sharnin V. Pavlov J. Ferreira R. Gomes M. Berta V. Weinzettl A. Malaquias B. Tl J. Zajac G. Mank F. J.R. Simes I. El Chama Neto H. Figueiredo N. Dreval D. Nurov A. W. Kraemer-Flecken B. Brotas P. Carvalho S. Zoletnik Y. Kuznetsov L. Ruchko H. Hegazy A. Ovsyannikov R. Coelho A. Duarte J. Santos H. Hegazy G. M. Vorobjev E. Sukhov A. Singh G. Kirnev V. Budaev J. Figueiredo G. Ramos L. I. Krupnik I. Nedzelski A. Neto

Publication Name: Nuclear Fusion

Publication Date: 2009-09-21

Volume: 49

Issue: 10

Page Range: Unknown

Description:

This paper presents an overview of the results obtained during the Joint Experiments organized in the framework of the IAEA Coordinated Research Project on 'Joint Research Using Small Tokamaks' that have been carried out on the tokamaks CASTOR at IPP Prague, Czech Republic (2005), T-10 at RRC 'Kurchatov Institute', Moscow, Russia (2006), and the most recent one at ISTTOK at IST, Lisbon, Portugal, in 2007. Experimental programmes were aimed at diagnosing and characterizing the core and the edge plasma turbulence in a tokamak in order to investigate correlations between the occurrence of transport barriers, improved confinement, electric fields and electrostatic turbulence using advanced diagnostics with high spatial and temporal resolution. On CASTOR and ISTTOK, electric fields were generated by biasing an electrode inserted into the edge plasma and an improvement of the global particle confinement induced by the electrode positive biasing has been observed. Geodesic acoustic modes were studied using heavy ion beam diagnostics on T-10 and ISTTOK and correlation reflectometry on T-10. ISTTOK is equipped with a gallium jet injector and the technical feasibility of gallium jets interacting with plasmas has been investigated in pulsed and ac operation. The first Joint Experiments have clearly demonstrated that small tokamaks are suitable for broad international cooperation to conduct dedicated joint research programmes. Other activities within the IAEA Coordinated Research Project on Joint Research Using Small Tokamaks are also overviewed. © 2009 IAEA, Vienna.

Open Access: Yes

DOI: 10.1088/0029-5515/49/10/104026

Joint experiments on the Tokamaks CASTOR and Ta10

E. Dufkova J. Brotankova M. Berta R. Dejarnac A. Fonseca G. M. Vorobjev A. Talebitaher J. Sentkerestiova B. Tál R. Gonzales V. Soldatov E. Sukhov I. Ďuran I. El Chama Neto C. R.Gutierrez Tapia A. W. Kraemeraflecken J. Ferreira A. Singh H. Hegazy H. Hegazy P. Khorshid L. Ruchko G. Kirnev N. Kirneva E. Del Bosco V. Vershkov A. Malaquias M. Hron B. Kuteev G. Mank M. Gryaznevich L. I. Krupnik V. Budaev A. Ovsyannikov A. Melnikov G. Van Oost M. Sokolov Y. Kuznetsov P. Peleman J. Zajac S. Zoletnik V. Weinzettl J. Stockel

Publication Name: Aip Conference Proceedings

Publication Date: 2008-12-01

Volume: 996

Issue: Unknown

Page Range: 24-33

Description:

Small tokamaks may significantly contribute to the better understanding of phenomena in a wide range of fields such as plasma confiement and energy transport; plasma stability in different magnetic configurations; plasma turbulence and its impact on local and global plasma parameters; processes at the plasma edge and plasmaawall interaction; scenarios of additional heating and nonainductive current drive; new methods of plasma profile and parameter control; development of novel plasma diagnostics; benchmarking of new numerical codes and so on. Furthermore, due to the compactness, flexibility, low operation costs and high skill of their personnel small tokamaks are very convenient to develop and test new materials and technologies. Small tokamaks are suitable and important for broad international cooperation, providing the necessary environment and manpower to conduct dedicated joint research programmes. In addition, the experimental work on small tokamaks is very appropriate for the education of students, scientific activities of postagraduate students and for the training of personnel for large tokamaks. The first Joint (Host Laboratory) Experiment (JE1) has been carried out in 2005 on the CASTOR tokamak at the IPP Prague, Czech Republic. It was jointly organized by the IPPaASCR and KFKI HAC, Budapest, involved 20 scientists from 7 countries and was supported through the IAEA and the ICTP, Trieste. The objective of JE1 was to perform studies of plasma edge turbulence and plasma confinement. Following the success of JE1, JE2 has been performed on Ta10 at RRC "Kurchatov Institute" in Moscow; 30 scientists from 13 countries participated in this experiment. This experiment aimed to continue JE1 turbulence studies, now extending them to the plasma core. Results of JE1 and JE2 will be overviewed and compared. © 2008 American Institute of Physics.

Open Access: Yes

DOI: 10.1063/1.2917019