The density, the electron, ion, and neutral temperatures in dense (ne>1013 cm-3) and cool (Te<8 eV) magnetized helium plasma columns submerged in a cool neutral gas (n0∼3×1015 cm-3) environment have been measured. These plasmas, of similar collisionality to those expected in the scrape-off layer of ITER (International Thermonuclear Experimental Reactor) [R. Parker, Contrib. Plasma Phys. 34, 422 (1994)], are found to obey the low-recycling behavior of approximate plasma pressure balance along the column axis. Density decreases by a factor of about 2 and Te remains isothermal. Computer simulations using the B2 [R. Schneider et al., J. Nucl. Mater. 196-198, 810 (1992)] plasma-fluid code have been performed and are in good agreement with experimental results. Measured ion temperatures are consistent with classical energy transfer from the electrons. Neutrals within the plasma are heated by elastic and charge-exchange collisions. This set of measurements represents the most detailed comparisons between experimental results and B2 predictions.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics