Geodesic mode instability driven by electron and ion fluxes during neutral beam injection in tokamaks

0477306 - ÚFP 2018 RIV NL eng J - Journal Article
Camilo de Souza, F. - Elfimov, A. - Galvão, R.M.O. - Krbec, Jaroslav - Seidl, Jakub - Stöckel, Jan - Hron, Martin - Havlíček, Josef - Bogár, Klára
Geodesic mode instability driven by electron and ion fluxes during neutral beam injection in tokamaks.
Physics Letters. A. Roč. 381, č. 36 (2017), s. 3066-3070. ISSN 0375-9601. E-ISSN 1873-2429
R&D Projects: GA ČR(CZ) GA16-25074S; GA ČR(CZ) GA14-35260S; GA MŠMT(CZ) 8D15001; GA MŠMT(CZ) LM2015045
Institutional support: RVO:61389021
Keywords : Tokamak * Geodesic acoustic modes * Kinetic theory * Instability * Landau damping
OECD category: 1.3 Physical sciences
Impact factor: 1.863, year: 2017
http://www.sciencedirect.com/science/article/pii/S0375960117306989

The effect of a minor concentration of energetic particles produced by parallel NB injection on Geodesic Acoustic Modes (GAM) spectrum is analyzed using fully kinetic equation. It is found that the GAM frequency is reduced by the effective mass renormalization due to that new energetic GAM appears with higher frequency. The electron current in combination with NB driven ion flow, modeled by shifted Maxwell distribution, may overcome the ion Landau damping thus resulting in the GAM instability when electron current velocity is larger than the effective parallel GAM phase velocity Rq omega Qualitative agreement of the theory with co/counter NB injection experiments in COMPASS tokamak is demonstrated.
Permanent Link: http://hdl.handle.net/11104/0273839