Particle Simulation Study of the Effect of Radial Electric Field on Scrape-off Layer Plasma and Sheath Formation
✍ Scribed by T. Takizuka; M. Hosokawa
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 122 KB
- Volume
- 40
- Category
- Article
- ISSN
- 0005-8025
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✦ Synopsis
Effects of radial electric field on scrape-off layer (SOL) plasma and sheath formation are studied by the use of a particle simulation code PARASOL. Previous theory for the magnetic presheath is confirmed by the simulation. The flow pattern and the density profile in the SOL plasma become asymmetric due to the E r ×B drift. The condition of the sheath formation is clarified; at the sheath entrance, the flow velocity normal to the divertor plate is larger than a specific sound speed projected in the normal direction. The asymmetry of the SOL plasma is principally brought by this boundary condition. The asymmetry becomes large with the increase of E r ×B drift velocity. When the velocity exceeds a critical value, the detached divertor with very low density is formed in a divertor region where E r ×B drift flows out from the plate.