TU Darmstadt, Darmstadt
During the last two years, the S-DALINAC operation suffered severely from cold leaks. These leakages were hard to localize and vanished sometimes without any obvious reason or showed up again depending on the thermo-cycle. Finally, the gaskets, sealing the cavity against the helium reservoir, were found to be the reason for this behaviour. We will report on the findings itself, the systematic becoming obvious and the solution chosen to ensure tightness in the future. Moreover, we will give a status report on two ongoing projects in Darmstadt. First the injector upgrade where a new cryo-module is built, housing two cavities and improved power couplers and secondly the cavity performance improvement by heat treatment at 850 C in an UHV oven.
