EROSION OF PLASMA-FACING COMPONENTS UNDER SIMULATED DISRUPTION-LIKE CONDITIONS USING AN ELECTROTHERMAL PLASMA GUN

The NCSU electrothermal plasma gun, SIRENS, has been used to evaluate the erosion behavior of plasma-facing components under conditions simu lating plasma disruption in tokamaks. The device is capable of produci ng conditions with heat fluence up to 10 MJ/m(2) over 0.1 and 0.25 ms pulse duration. In future large tokamaks, plasma-facing components are expected to receive heat fluxes during a plasma disruption, which may exceed 100 GW/m(2) over 0.01-5 ms. The vapor, which is developed at t he ablating surface, absorbs a fraction of the incoming plasma energy. Candidate plasma-facing materials have been exposed to heat fluxes in the SIRENS facility (primarily from a blackbody spectrum photons), up to 100 GW/m(2) over 0.1-0.25 ms. The vapor shielding effect has been demonstrated and analyzed for the divertor candidate materials.