Theory and simulation of dust transport in Tokamaks

This project involves computational and theoretical studies of dust (i.e., small solid particles) in tokamak plasmas. Such particles originate from the plasma facing components of the device, and are routinely observed in tokamaks. They represent a critical issue for ITER, for two reasons. Firstly, dust might enter the high temperature core region, and evaporate there. This would be serious source of impurities which could fatally contaminate the plasma. Secondly, solid objects immersed in the plasma absorb Tritium. Thus any dust which survives a shot or which leaves the plasma represents a radiological safety hazard. Thus it is important to assess how dust grains move around the tokamak. We will make such an assessment. In order to do so the basic dust-plasma interaction must be studied in detail. This is neccessary to establish, for instance, how the local plasma conditions determine the energy and particle fluxes onto the dust grain, and thus its temperature, evaporation rate, etc. These studies will be carried out both computationally and analytically, and information from them will be used in a realistic simulation of dust dynamics in a tokamak plamsa.