Kinetic effects in tokamak scrape-off layer plasmas

Journal Article · Thu May 01 04:00:00 EDT 1997 · Physics of Plasmas

OSTI ID:656076

Krasheninnikov, S I; Batishcheva, A A; Sigmar, D J ^[1]; Catto, P J ^[2]; Xu, X Q; Byers, J A; Rognlien, T D; Cohen, R H ^[3]; Shoucri, M M; Shkarofskii, I P ^[4]; Batishchev, O V

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1. Massachusetts Institute of Technology, Plasma Fusion Center, Cambridge, Massachusetts 02139 (United States)
2. Lodestar Research Corporation, Boulder, Colorado (United States)
3. Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (United States)
4. Centre Canadien de Fusion Magnetique, Varennes, Quebec J3X 1S1 (Canada)

The short mean-free path expansion used in fluid modeling of scrape-off layer plasmas is often violated for typical discharge parameters, especially by the superthermal particles, which carry most of the heat flux. Thus, the tail of the distribution function can strongly depart from Maxwellian due to nonlocal mean-free path effects, which can modify plasma transport, impurity radiation, and plasma{endash}neutral gas interactions. These nonlocal effects become particularly pronounced for detached plasma conditions that are characterized by sharp gradients in the plasma parameters along the magnetic field. These problems are being addressed by developing one spatial dimension and two velocity variables, fully kinetic, collisional, and time-dependent particle-in-cell code, W1 [Contrib. Plasma Phys. {bold 34}, 436 (1994)], and its parallel-computer version, PW1 [Contrib. Plasma Phys. {bold 34}, 424 (1996)]. Comparisons are made with the Fokker{endash}Planck code ALLA [Phys. Plasmas {bold 3}, 1634 (1996)] and with experimental results. Kinetic effects on probe measurement interpretation, impurity radiation, and parallel heat conductivity due to non-Maxwellian features in scrape-off layer plasmas are considered. Heat conductivity is compared with {ital ad hoc} heat flux limit models. {copyright} {ital 1997 American Institute of Physics.}

• DOE Contract Number: FG02-88ER53263; FG02-91ER54109; W-7405-ENG-48
• OSTI ID: 656076
• Report Number(s): CONF-961102--
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 4; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BOUNDARY LAYERS
COLLISIONS
COMPUTER CODES
HEAT TRANSFER
KINETICS
MAGNETIC CONFINEMENT
MEAN FREE PATH
PARALLEL PROCESSING
PLASMA IMPURITIES
PLASMA SCRAPE-OFF LAYER
PLASMA SIMULATION
TOKAMAK DEVICES