The behavior of boron coatings under simultaneous ion bombardment and temperature cycling

Low Z boron coatings have been tested for stability under simulated fusion reactor conditions including simultaneous temperature cycling and ion implantation from the 1-B(n,α)7Li reaction. Boron coatings several microns thick, produced by vacuum evaporation onto heated titanium substrates, exhibited reasonable stability after doses of 3.8 x 1018 α/cm2 and 1320 temperature cycles from 165-4900C. These conditions correspond to exposures at the first wall of the fusion reactor, ranging from a few weeks to about six months, depending on the reactor design. (orig.)