A small, insertable oven for boronization

A small insertable oven for benchmarking the boronizing characteristics of solid compounds, such as decaborane and carborane, has been developed for the Phaedrus‐T tokamak. Assembly and installation of the oven are relatively easy as the oven design utilizes a Langmuir probe drive assembly, which is standard equipment on most tokamaks and allows the 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 of boron to carbon as compared to films deposited with trimethylboron, a gaseous compound. Overall plasma performance is not found to be greatly affected by whether decaborane, carborane or trimethylboron is used for boronization in Phaedrus‐T.