Existence of Weakly Damped Kinetic Alfven Eigenmodes in Reversed Shear Tokamak

N. N. Gorelenkov

关键词: CAUSALITY;    DAMPING;    KINETICS;    LARMOR RADIUS;    REVERSED SHEAR;    TOKAMAK DEVICES;    ALFVEN WAVES Tokomak;   

DOI  :  10.2172/953698
RP-ID  :  PPPL-4340
PID  :  OSTI ID: 953698
Others  :  TRN: US1004024

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

A kinetic theory of weakly damped Alfven Eigenmode (AE) solutions strongly interacting with the continuum is developed for tokamak plasmas with reversed magnetic shear. We show that the ideal MHD model is not sufficient for the eigenmode solutions if the standard causality condition bypass rule is applied. Finite Larmor radius effects are required, which introduce multiple kinetic subeigenmodes and collisionless radiative damping. The theory explains the existence of experimentally observed Alfvenic instabilities with frequencies sweeping down and reaching their minimum (bottom).