Geodesic mode instability driven by electron and ion fluxes in tokamaks

• Grant number: 15/22376-8
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: December 01, 2015
• End date: February 29, 2016
• Field of knowledge: Physical Sciences and Mathematics - Physics - Physics of Fluids, Plasma Physics and Electrical Discharge
• Principal Investigator: Artour Grigorievich Elfimov
• Grantee: Artour Grigorievich Elfimov
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/50773-0 - Center of excellence in physics and applications of plasmas, AP.TEM

Abstract

The effect of the parallel electron current and plasma flux on Geodesic Acoustic Modes (GAM) in a tokamak is analyzed by kinetic theory taking into the account the ion Landau damping and diamagnetic drifts. It is shown that the electron current and plasma flow, modeled by shifted Maxwell distributions of electrons and ions, may overcome the ion Landau damping generating the GAM instability when the parallel electron current velocity is larger than the effective parallel GAM phase velocity of sidebands, Rqw. The instability is driven by the electron current and the parallel ion flux cross term. Possible applications to tokamak experiments are discussed. Existence of the geodesic ion sound mode due to plasma flow is shown. (AU)