Particle and energy fluxes observed in the scrape-off layer of JFT-2 tokamak
Abstract
Particle and energy fluxes in the scrape-off layer produced by poloidal limiters are studied in the JFT-2 tokamak with mean electron densities of 1.3 x 10 to the 13th power and 2.8 x 10 to the 13th power/cu cm. The measurements were made by a combined Langmuir/thermoprobe and an infrared camera. The electron density in the scrape-off layer decays exponentially with increasing minor radius, implying that the cross-field diffusion is of the order of the Bohm diffusion. It is shown that heat transmission to the limiter more than 1 cm behind the edge radius is determined by a sheath of Maxwellian particles. Near the edge radius, accelerated electrons play a major role, which is indicated by toroidal anisotropy of the heat flux in the lower-density case.
- Publication:
-
Nuclear Fusion
- Pub Date:
- June 1978
- Bibcode:
- 1978NucFu..18..849G
- Keywords:
-
- Diffusion Coefficient;
- Flux Density;
- Heat Transmission;
- Particle Energy;
- Tokamak Devices;
- Electron Density (Concentration);
- Electrostatic Probes;
- Infrared Photography;
- Plasma Decay;
- Stellarators;
- Thermocouples;
- Plasma Physics