A KINETIC-MODEL OF TRANSIENT EFFECTS IN TOKAMAK EDGE PLASMAS

Fluid descriptions are not adequate for edge plasma studies when the h igh collision frequency assumption fails in the presence of rapid tran sient processes. The results of analytic and numerical modeling of som e of the non-Maxwellian features of edge plasma transport associated w ith transient heating and cooling phenomena in the scrape-off layer ar e presented, It is found that kinetic effects alter the heat conductio n coefficient and lead to interesting critical behavior of the distrib ution function. The numerics are performed with the recently developed time-dependent Fokker-Planck code ALLA. (C) 1996 American Institute o f Physics.