Scaling of divertor conditions in ITER/NET with density, power, SOL transport, pitch, size, and particle throughput

Abstract

Scaling laws for the divertor conditions to be expected in a next step device, ITER, are derived from 2D modelling. Model calculations are carried out for varying density, power, transport coefficients, pitch, size and particle throughput. In the low temperature, high recycling domain, the peak power, the electron temperature, and the particle density at the plate are found to be extremely sensitive to upstream parameters, especially to upstream density. Low density, high power operation therefore remains very demanding for the divertor. For operation at a critical density, for which the electron temperature at the point of peak power load is a fixed low value, the peak power load scales more gently, proportional to the power density flowing into the scrape-off layer. Precise control of the density is required to maintain this temperature