Observation of ion temperature gradient mode and evaluation of fluctuation-driven heat flux in a linear magnetized plasma

2014 Fiscal Year Final Research Report

• Project/Area Number: 23360414
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: Kyushu University
• Principal Investigator: INAGAKI Shigeru 九州大学, 応用力学研究所, 教授 (60300729)
• Co-Investigator(Renkei-kenkyūsha): KASUYA Naohiro 九州大学, 応用力学研究所, 准教授 (20390635) ; SASAKI Makoto 九州大学, 応用力学研究所, 助教 (70575919) ; EZUMI Naomichi 長野工業高等専門学校, 電子制御工学科, 准教授 (20321432)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: プラズマ乱流 / イオン温度勾配不安定性 / 温度揺動 / 熱輸送

Outline of Final Research Achievements

In fusion plasmas, radial ion heat transport driven by ion temperature gradient (ITG) instability is considered to be dominant. Here we have observed ITG-like fluctuations and developed analysis method for evaluating a fluctuation-driven heat transport in the linear plasma device. The main results are the following: (1) We calculated the linear growth rate of ITG modes by a three-field fluid model and found unstable domain. Then we have succeeded to observe a fluctuation propagating in the ion diamagnetic drift direction, which co-exists with drift waves propagating in the electron diamagnetic drift direction. (2) We developed a conditional sampling method and succeeded to extract the ion temperature fluctuation amplitude synchronized with the floating potential fluctuation. In addition, we improved the method and observed the phase difference between temperature and potential fluctuations, which allows us to evaluate the fluctuation-driven heat flux.

Free Research Field

プラズマ物理学