Electron heat transport in a steep temperature gradient

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Phys Fluids B; (United States)

DOI:https://doi.org/10.1063/1.859139· OSTI ID:6202181

Rogers, J H; De Groot, J S; Abou-Assaleh, Z; Matte, J P; Johnston, T W; Rosen, M D

Temporal and spatial measurements of electron heat transport are made in the University of California Davis AURORA device (J. H. Rogers, Ph.D. dissertation, University of California, Davis, 1987). In AURORA, a microwave pulse heats a region of underdense, collisional, plasma (n/n/sub cr/ approx. <1, where n/sub cr/ = 1.8 x 10/sup 10/ cm/sup -3/ is the critical density, T/sub e//sub 0/ approx. =0.15 eV, and the electron scattering mean free path lambda/sub perpendicular/approx. >2 cm). In this region, strong thermal heating (T/sub c/ approx. <0.7 eV) as well as suprathermal heating (T/sub h/approx. =3 eV) is observed. The strong heating results in a steep temperature gradient that violates the approximations of classical heat diffusion theory (L/sub T//lambda/sub perpendicular/approx. >3 for thermal electrons, where L/sub T/ = T/sub c/(partialT/sub c//partialz)/sup -1/ is the cold electron temperature scale length. The time evolution of the electron temperature profile is measured using Langmuir probes. The measured relaxation of the temperature gradient after the microwave pulse is compared to calculations using the Fokker--Planck International code (Phys. Rev. Lett. 49, 1936 (1982)) and the multigroup, flux-limited, target design code LASNEX (Comm. Plasma Phys. 2, 51 (1975)). The electron distribution function at the end of the microwave pulse is used as initial conditions for both codes. The Fokker--Planck calculations are found to agree very well with the measurements.

• Research Organization: Department of Applied Science, University of California Davis, Davis, California 95616
• OSTI ID: 6202181
• Journal Information: Phys Fluids B; (United States), Journal Name: Phys Fluids B; (United States) Vol. 1:4; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
AURORA FACILITY
COLLISIONAL PLASMA
CORRELATIONS
ELECTRIC PROBES
ELECTROMAGNETIC RADIATION
ELECTRON TEMPERATURE
ENERGY TRANSFER
HEAT TRANSFER
HEATING
LANGMUIR PROBE
MEAN FREE PATH
MICROWAVE RADIATION
PLASMA
PLASMA DIAGNOSTICS
PLASMA HEATING
PROBES
RADIATIONS
SCATTERING
TEMPERATURE GRADIENTS