NUMERICAL-ANALYSIS OF THE PLASMA MATERIAL INTERACTION DURING THE THERMAL QUENCH PHASE OF TOKAMAK DISRUPTIONS

Plasma disruptions in a next generation tokamak will cause high surface energy deposition on the surface of the plasma facing components. After the onset of the energy deposition a series of complex processes develops which are commonly termed as ''vapour shielding''. The vapour shield developing in front of the heated material surface may attenuate a part of the incident energy and cause a reduction in the energy which is actually deposited in the plasma facing material. The present paper describes a numerical model for these processes which includes the thermophysical response of the plasma facing material, the magnetohydrodynamic development of the plasma vapour cloud, and the radiation transfer within the vapour cloud. Results of the calculations for an incident energy of 10 MJ m-2 during 0.1 ms using the local thermodynamic equilibrium model are presented. Compared to a calculation without vapour shield the carbon erosion is reduced by 98.9%.