TY - JOUR
T1 - IShTAR ICRF antenna field characterization in vacuum and plasma by using probe diagnostic
AU - Usoltceva, Mariia
AU - Ochoukov, Roman
AU - D'Inca, Rodolphe
AU - Jacquot, Jonathan
AU - Crombé, Kristel
AU - Kostic, Ana
AU - Heuraux, Stéphane
AU - Faudot, Eric
AU - Noterdaeme, Jean Marie
N1 - Publisher Copyright:
© 2017 The authors, published by EDP Sciences.
PY - 2017/10/23
Y1 - 2017/10/23
N2 - RF sheath physics is one of the key topics relevant for improvements of ICRF heating systems, which are present on nearly all modern magnetic fusion machines. This paper introduces developement and validation of a new approach to understanding general RF sheath physics. The presumed reason of enhanced plasma-antenna interactions, parallel electric field, is not measured directly, but proposed to be obtained from simulations in COMSOL Multiphysics® Modeling Software. Measurements of RF magnetic field components with B-dot probes are done on a linear device IShTAR (Ion cyclotron Sheath Test ARrangement) and then compared to simulations. Good resulting accordance is suggested to be the criterion for trustworthiness of parallel electric field estimation as a component of electromagnetic field in modeling. A comparison between simulation and experiment for one magnetic field component in vacuum has demonstrated a close match. An additional complication to this ICRF antenna field characterization study is imposed by the helicon antenna which is used as a plasma ignition tool in the test arrangement. The plasma case, in contrast to the vacuum case, must be approached carefully, since the overlapping of ICRF antenna and helicon antenna fields occurs. Distinguishing of the two fields is done by an analysis of correlation between measurements with both antennas together and with each one separately.
AB - RF sheath physics is one of the key topics relevant for improvements of ICRF heating systems, which are present on nearly all modern magnetic fusion machines. This paper introduces developement and validation of a new approach to understanding general RF sheath physics. The presumed reason of enhanced plasma-antenna interactions, parallel electric field, is not measured directly, but proposed to be obtained from simulations in COMSOL Multiphysics® Modeling Software. Measurements of RF magnetic field components with B-dot probes are done on a linear device IShTAR (Ion cyclotron Sheath Test ARrangement) and then compared to simulations. Good resulting accordance is suggested to be the criterion for trustworthiness of parallel electric field estimation as a component of electromagnetic field in modeling. A comparison between simulation and experiment for one magnetic field component in vacuum has demonstrated a close match. An additional complication to this ICRF antenna field characterization study is imposed by the helicon antenna which is used as a plasma ignition tool in the test arrangement. The plasma case, in contrast to the vacuum case, must be approached carefully, since the overlapping of ICRF antenna and helicon antenna fields occurs. Distinguishing of the two fields is done by an analysis of correlation between measurements with both antennas together and with each one separately.
UR - http://www.scopus.com/inward/record.url?scp=85032630996&partnerID=8YFLogxK
U2 - 10.1051/epjconf/201715703058
DO - 10.1051/epjconf/201715703058
M3 - Conference article
AN - SCOPUS:85032630996
SN - 2101-6275
VL - 157
JO - EPJ Web of Conferences
JF - EPJ Web of Conferences
M1 - 03058
T2 - 22nd Topical Conference on Radio-Frequency Power in Plasmas 2017
Y2 - 30 May 2017 through 2 June 2017
ER -