Stability analysis of alpha driven toroidal Alfvén eigenmodes observed in JET deuterium-tritium internal transport barrier plasmas

Nuclear Fushion

article

M. Fitzgerald¹  R. Dumont²  D. Keeling¹  J. Mailloux¹  S. Sharapov¹  M. Dreval³  A. Figueiredo⁴  R. Coelho⁴  J. Ferreira⁴  P. Rodrigues⁴  F. Nabais⁴  D. Borba⁴  Ž. Štancar¹  G. Szepesi¹  R.A. Tinguely⁵  P.G. Puglia⁶  H.J.C. Oliver¹  V. Kiptily¹  M. Baruzzo⁷  M. Lennholm¹  P. Siren¹  J. Garcia²  C.F. Maggi¹ 

[1] United Kingdom Atomic Energy Authority, Culham Science Centre;CEA;National Science Center ‘Kharkov Institute of Physics and Technology’;Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa;MIT Plasma Science and Fusion Center;Ecole Polytechnique Fédérale de Lausanne ,(EPFL), Swiss Plasma Center;Dip.to Fusione e Tecnologie per la Sicurezza Nucleare

关键词: JET DT;    TAE;    Alfvén;    MHD;    fast particle;    ITB;    afterglow;   

DOI  :  10.1088/1741-4326/acee14

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

A toroidal Alfvén eigenmode (TAE) has been observed to be driven by alpha particles in a JET deuterium-tritium internal transport barrier plasma. The observation occurred 50 ms after the removal of neutral beam heating (NBI). The mode is observed on magnetics, soft-xray, interferometry and reflectometry measurements. We present detailed stability calculations using a similar tool set validated during deuterium only discharges. These calculations strongly support the conclusion that the observed mode is a TAE, and that this mode was destabilized by alpha particles. Non-ideal effects from the bulk plasma are interpreted as responsible for suppressing the majority of TAEs which were also driven by alpha particles, but the modes that match the observations are predicted to be particularly weak for these non-ideal effects. This mode located far from the core on the outboard midplane is found to be driven by both trapped and passing particles despite alpha particles originating in the core.

【 授权许可】

Unknown