LIF studies for TiN, TiC coating modification by ion sputtering

The application of a coating to some elements of the vacuum vessel has been widely used in fusion devices during the last decade. As a rule, this results in a decrease in impurity concentrations in the plasma and a decrease in the radiation losses. TiC and TiN coatings are the most stable binary coatings in a plasma environment. However up till now the changing properties of the coatings themselves, in a plasma environment have not been properly studied. For example, there are contradictions with respect to the depth of stoichiometric composition changes (depletion of the lighter component in binary coatings). The aim of these experiments is to compare the results of partial sputtering coefficient measurements for metal titanium and TiN, TiC coatings, and the depth distribution of N atoms in the TiN coating before and after H+ ion bombardment. We have used the LIF technique for measuring the sputtered Ti atom density and velocity distribution along the normal to the bombarded surface, and the nuclear reaction method for studying the N atom depth distribution. (orig./AH)