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Parameter study of ICRH wave propagation in IShTAR

Published online by Cambridge University Press:  04 March 2016

K. Crombé*
Affiliation:
Department of Applied Physics, Ghent University, 9000 GENT, Belgium LPP-ERM/KMS, EUROfusion Consortium Member, Trilateral Euregio Cluster, Royal Military Academy, 1000 Brussels, Belgium
D. Van Eester
Affiliation:
LPP-ERM/KMS, EUROfusion Consortium Member, Trilateral Euregio Cluster, Royal Military Academy, 1000 Brussels, Belgium
*
Email address for correspondence: [email protected]

Abstract

A crude first assessment of how waves behave is commonly made relying on decoupled dispersion equation roots. In the low density, low temperature region behind the last closed flux surface in a tokamak – where the density decays exponentially and where the lower hybrid resonance is crossed but where the thermal velocity is small enough to justify dropping kinetic (hot plasma) effects – the study of the wave behaviour requires the roots of the full cold plasma dispersion equation. The IShTAR (Ion cyclotron Sheath Test ARrangement) device will be adopted in the coming years to shed light on the dynamics of wave–plasma interactions close to radio frequency (RF) launchers and in particular on the impact of the waves on the density and their role in the formation of RF sheaths close to metallic objects. As IShTAR is incapable of mimicking the actual conditions reigning close to launchers in tokamaks; a parameter range needs to be identified for the test stand to permit highlighting of the relevant wave physics. Studying the coupled dispersion equation roots allowed us to find a suitable operation domain for performing experiments.

Type
Research Article
Copyright
© Cambridge University Press 2016 

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References

Bobkov, V. et al. 2013 ICRF operation with improved antennas in ASDEX upgrade with W wall. Nucl. Fusion 53 (9), 093018.Google Scholar
Brambilla, M. 1998 Kinetic Theory of Plasma Waves: Homogeneous Theory. Clarendon.Google Scholar
Crombé, K. et al. 2015 Studies of RF sheaths and diagnostics on IShTAR. In AIP Conference Proc., Proceedings of the 21st Topical Conference on Radiofrequency Power in Plasmas, UCLA Conference Center at Lake Arrowhead, California, 030006.Google Scholar
Faudot, E. et al. 2015 A linear radio frequency plasma reactor for potential and current mapping in a magnetized plasma. Rev. Sci. Instrum. 86 (6), 063502.Google Scholar
D’Inca, R. et al. 2015 IShTAR: a test facility to investigate sheaths effects during ion cyclotron resonance heating (in preparation).Google Scholar
Jacquet, Ph. et al. 2014 Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like wall. Phys. Plasmas 21, 061510.Google Scholar
Klepper, C. C. et al. 2013 RF sheath-enhanced beryllium sources at JET’s ICRH antennas. J. Nucl. Mater. 7 (438), S594S598.CrossRefGoogle Scholar
Lerche, E. et al. 2014a Impact of minority concentration on fundamental (H)D ICRF heating performance in JET-ILW. Nucl. Fusion 54 (7), 073006.Google Scholar
Lerche, E. et al. 2014b 2014-2 Impact of localized gas injection on ICRF coupling and SOL parameters in JET-ILW H-mode plasmas. In Proc. 21st International Conference on Plasma Surface Interactions, P1-061, EFDA report version: EFDAJETCP(14)01/18.Google Scholar
Louche, F. et al. 2015 Studies of RF sheaths and diagnostics on IShTAR. In AIP Conference Proc., Proceedings of the 21st Topical Conference on Radiofrequency Power in Plasmas, UCLA Conference Center at Lake Arrowhead, California, 070016.Google Scholar
Noterdaeme, J.-M. et al. 2008 Physics studies with the additional heating systems in JET. Fusion Sci. Technol. 53, 01103.CrossRefGoogle Scholar
Noterdaeme, J.-M. et al. 2015 Innovations that make use of the ion cyclotron range of frequency power suitable for fusion reactors, to be presented at the 25th International Toki Conference, Toki (Japan).Google Scholar
Ochoukov, R. et al. 2014 ICRF-enhanced plasma potentials in the SOL of Alcator C-Mod. Plasma Phys. Control Fusion 56 (1), 015004.Google Scholar
Stix, T. H. 1992 Waves in Plasmas. Springer Science & Business Media.Google Scholar
Van Eester, D., Crombé, K. & Kyrytsya, V. 2013a Ion cyclotron resonance heating induced density modification near antennas. Plasma Phys. Control. Fusion 55, 025002.CrossRefGoogle Scholar
Van Eester, D., Crombé, K. & Kyrytsya, V. 2013b Connection coefficients for cold plasma wave propagation near metallic surfaces. Plasma Phys. Control. Fusion 55, 055001.CrossRefGoogle Scholar
Zhang, W. et al. 2015 3D simulations of gas puff effects on edge density and ICRF coupling in ASDEX upgrade. Nucl. Fusion (submitted for publication).CrossRefGoogle Scholar