An assessment of disruption erosion in the ITER environment

The behavior of divertor materials during a major disruption in ITER is very important to successful and reliable operation of the reactor. Erosion of material surfaces due to a thermal energy dump can severely limit the lifetimes of plasma-facing components and thus diminish the reactor's economic feasibility. A comprehensive numerical model has been developed and used in this analysis, which includes all major physical processes taking place during plasma/material interactions. Models to account for material thermal evolution, plasma/vapor interaction physics, and models for hydrodynamic radiation transport in the developed vapor cloud are implemented in a self-consistent manner to realistically assess disruption damage. The extent of self-protection from the developed vapor cloud in front of the incoming plasma particles is critically important in determining the overall disruption lifetime. Models to study detailed effects of the strong magnetic field on the behavior of the vapor cloud and on the net erosion rate have been developed and analyzed. Candidate materials such as beryllium and carbon are both considered in this analysis. The dependence of divertor disruption lifetime on disruption physics and reactor conditions was analyzed and discussed. (orig.)