A SMALL, INSERTABLE OVEN FOR BORONIZATION

A small insertable oven for benchmarking the boronizing characteristic s of solid compounds, such as decaborane and carborane, has been devel oped for the Phaedrus-T tokamak. Assembly and installation of the oven are relatively easy as the oven design utilizes a Langmuir probe driv e assembly, which is standard equipment on most tokamaks and allows th e oven to be inserted into the tokamak without requiring a vent. Films deposited by heating carborane into the vapor state with the oven are found to be spatially nonuniform in both thickness and in the ratio o f boron to carbon as compared to films deposited with trimethylboron, a gaseous compound. Overall plasma performance is not found to be grea tly affected by whether decaborane, carborane or trimethylboron is use d for boronization in Phaedrus-T. (C) 1996 American Institute of Physi cs.