An evaluation of kinetic effects in the DIII-D divertor

JOURNAL OF NUCLEAR MATERIALS

卷:266

Article; Proceedings Paper

Watkins, JG ; Batishchev, O ; Boedo, J ; Hill, DN ; Lasnier, CJ ; Lehmer, R ; Leonard, AW ; Moyer, RA

关键词: detached plasma;    DIII-D;    divertor modeling;    Langmuir probe;    plasma edge physics;    scrape off layer;    SOL modeling;    velocity distribution;   

DOI  :  10.1016/S0022-3115(98)00556-X

来源: Elsevier

【 摘 要 】

Under certain conditions, high temperature electrons diffusing across the separatrix near the midplane can propagate to the divertor without collision and produce a high energy tail in the electron distribution function near the separatrix. We evaluate a kinetic criterion along the field using measurements from divertor Thomson scattering and compare temperature measurements from target plate Langmuir probes to estimate the magnitude of the high energy tail. A Fokker-Planck kinetic model [O. Batishchev, Phys. Plasmas 4 (1998) 1672], which includes electron-electron, electron-ion, electron-neutral, and charge exchange interactions is used to estimate the size of the high energy tail. For the cases considered, we found less than 1% of non-thermal particles near the target plate at typical densities and power levels for the DIII-D scrape-off layer plasma. ELMs violate our kinetic criterion. (C) 1999 Elsevier Science B.V. All rights reserved.

【 授权许可】

Free