E×B-drift, current, and kinetic effects on divertor plasma profiles during ELMs

The transient heat load on divertor surfaces from edge-localized modes (ELMs) in tokamaks can be very large and thus of concern for a large device such as ITER. Models for kinetic modifications to fluid models are discussed that should allow a reasonable description of the long mean-free path regime encountered owing to the high plasma temperatures in the scrape-off layer (SOL) during large ELMs. A set of two-dimensional simulations of the dynamic response of the SOL plasma to an ELM is presented. The role of plasma currents and E×B motion is emphasized, which cause large changes in divertor density and temperature, but small changes in the outer-plate heat flux.