Observation of Lower Hybrid Current Drive Improved Confinement with a Graphite Probe at the Last Closed Flux Surface of the HT-7 Tokamak

• 来源期刊: 中国物理快报（英文版）
• 学科: 物理学
• 年，卷（期）: 2002,（9）
• 页码范围: 1316-1318
• 页数: 3页
• 分类号: O4
• 语种: 英文

摘要

High time resolution measurements of the electrostatic fluctuations, radial electric field Er and turbulence-induced electron flux Гe have been performed across the transition of lower hybrid current drive improved confinement with a graphite Langmuir probe array at the last closed flux surface of the HT-7 tokamak. The decrease of Гe is dominated by the suppression of fluctuation levels, which follows the change of Er. A reversal of the poloidal propagation direction of turbulence demonstrates that the poloidal propagation is dominated by Eт× Bφ drift. The enhancement of poloidal coherence accompanies the fluctuation suppression, which suggests the subtle variation of turbulence features.