| This thesis continues studies on thermo-oxidation as a method for the removal of tokamak codeposits. Oxidation conditions were extended to pressures ≤ 79kPa and temperatures ≤ 673 K. Codeposit specimens with a variety of compositions, densities and thicknesses were taken from DIII-D and JET. It was confirmed that increasing the temperature and pressure improves the effectiveness of codeposit removal as measured by the initial D removal rate and by the final D content after prolonged oxidation. The removal effectiveness is much more sensitive to changes in temperature than to changes in pressure. Of particular importance, the initial D removal rates were found to increase linearly with increasing inherent D content independent of Be content, ranging from 0-60% Be/(Be+C), and thickness, ranging from 10-270 mum. The total amount of D removed does not appear to be affected by thickness or beryllium content of the JET codeposits. In contrast, the DIII-D codeposits show the D removal efficiency decreasing with increasing inherent boron content. |
