Study on the boundary condition of spontaneously excited Alfven wave and relaxation of anisotropy in a mirror magnetic field configuration

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17797
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Plasma science
• Research Institution: University of Tsukuba
• Principal Investigator: IKEZOE Ryuya 筑波大学, 数理物質系, 助教 (70582849)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 波動計測 / マイクロ波反射計 / AIC波動 / ICRF加熱 / 高エネルギーイオン計測 / 温度非等方性 / スイッチングアンテナ / 波動粒子相互作用

Outline of Final Research Achievements

Alfven ion cyclotron wave is excited due to strong anisotropy of ion temperature, which is generated by ICRF heating in the GAMMA 10 tandem mirror device. Multiple AIC waves are simultaneously excited in an unstable frequency band as discrete peaks, of which spatial structure has been investigated by developing a two-channel microwave reflectometer with fast antenna switching. The radial profile, axial variation at five positions and phase profile of the density fluctuations accompanied by the AIC waves have been successfully measured along with those temporal evolution. A clear difference in the axial profile has been found among the AIC waves for the first time. In addition, it is indicated that the difference waves are generated by nonlinear coupling among the AIC waves, which contribute to the relaxation of temperature anisotropy.

Free Research Field

プラズマ物理