Non-inductive formation of overdense spherical tokamak with EB wave in the first propagation band by Gaussian beams

2016 Fiscal Year Final Research Report

• Project/Area Number: 26249142
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: Kyoto University
• Principal Investigator: Tanaka Hitoshi 京都大学, エネルギー科学研究科, 教授 (90183863)
• Co-Investigator(Kenkyū-buntansha): 前川 孝 京都大学, エネルギー科学研究科, 名誉教授 (20127137) ; 打田 正樹 京都大学, エネルギー科学研究科, 助教 (90322164)
• Project Period (FY): 2014-06-27 – 2017-03-31
• Keywords: 電子バーンスタイン波加熱・電流駆動 / オーバーデンスプラズマ / モード変換 / トカマクの無誘導形成 / 球状トカマク

Outline of Final Research Achievements

When the 1st electron cyclotron resonance (ECR) layer is located at the plasma core, the 2nd harmonic ECR layer is near the outboard vessel wall, the upper hybrid resonance layer is located between them and the left-handed polarized electromagnetic wave is launched obliquely to the toroidal magnetic field from the outboard side of the torus, then, extremely overdense spherical tokamak plasmas are produced non-inductively with the electron density of ~6 times the plasma cutoff density. Injected electromagnetic wave is mode-converted to electrn Bernstein wave and absorbed along the propagation path firstly by high energy electrons at the Doppler-shifted ECR in the low field side, next by bulk electrons at the 1st ECR at the plasma center. Bulk electron temperature is increased at the plasma center, which results in the increase of the electron density. The degradation of heating and/or current drive by non-linear effects due to high power density is not observed with ~200kW injection.

Free Research Field

プラズマ理工学