Electron stimulated desorption from stainless steel at temperatures between −15 and +70 °C

Abstract

The electron stimulated desorption (ESD) yield from 316LN stainless steel was studied as a function of surface temperature in the range from −15 to +70 °C. The ESD yields as a function of electron dose for three samples kept at −5, +20 and +70 °C were found to be very similar. After long-term electron bombardment at fixed temperature, the ESD temperature dependence was also measured for each sample at temperatures between −15 and +70 °C. The results show that desorption yields increase with temperature, this dependence is small for H2 and increases with atomic mass number reaching the maximum difference of factor 3 for CO2. The main conclusion is that the vacuum chamber temperature in the range between −15 and +70 °C is not critical in most cases for accelerator vacuum system design. The change of ESD yield with temperature is relatively small compared to desorption yield uncertainties and the significant reduction observed with an accumulated electron dose.