PERFORMANCE OF BORON-CONTAINING MATERIALS UNDER DISRUPTION SIMULATIONS AND TOKAMAK DIVERTOR PLASMA TESTING

The behavior of thick B4C coatings on different graphites under high p ower electron beam irradiation, pulsed plasma irradiation and under DI II-D divertor plasma action was investigated. SiC-B4C coating on graph ites produced in General Atomics and pyrolytic boron nitride were also tested in the plasma gun device. In the following tests at these faci lities, the samples were examined using SIMS, EDAX, X-ray crystallogra phy, profilometry and Auger spectroscopy. B4C coatings showed excellen t durability under high heat flux irradiation and in conditions of rea l tokamak divertor plasma. The obtained results indicated that the use of RGT graphite (the graphite with high thermal conductivity) improve s the durability of the B4C coating significantly. Pyrolytic boron nit ride showed very small removal of the matter and no mechanical damage.