Simulation of non-Maxwellian electron velocity distributions in an inhomogeneous plasma driven by intense microwaves

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Bulletin of the American Physical Society

OSTI ID:67872

Matte, J P; Johnston, T W ^[1]; Liu, J M; De Groot, J S ^[2]; Drake, R P ^[3]

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1. INRS-Energie et Materiaux, Varennes, Quebec (Canada)
2. Univ. of California, Davis, CA (United States)
3. Pulp and Paper Research Institute of Canada, Pointe Claire (Canada)

Flat-topped electron velocity distributions, of the type exp ({minus}(v/u)**m), with m > 2, are observed in the UCD AURORA II device for inverse Bremsstrahlung heating with intense microwaves (V{sub osc}**2/V{sub e}**2 of order 1), in approximate agreement with electron kinetic simulations. Permanent magnets are arranged on the surface of the vacuum tank to confine the argon discharge plasma and to produce an axial density gradient. A microwave reflector limits the heating region to 0.7 N{sub c} to avoid any collective heating at the critical surface. The ionization fraction (1%) is high enough that charged particle collisions dominate. A short microwave pulse (- 0.2 to 2 {mu}s) creates a very steep temperature gradient (LT/l{sub ei} {approximately} 0.1 to 10). Langmuir probes are used to measure the electron distribution function in the plasmas. Results will be compared to nonlocal heat transport theory and Fokker-Planck calculations.

• OSTI ID: 67872
• Report Number(s): CONF-9310400--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 13 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOLTZMANN STATISTICS
DISTRIBUTION FUNCTIONS
ELECTRONS
INHOMOGENEOUS PLASMA
MICROWAVE HEATING
SIMULATION