Maintenance for DR(Pandora)

During the summer run the Helium consumption was about 20% higher than normal. After the run we opened the DR and checked for touch (none was found), we observed that the nitrogen shield was a bit loose so it was tightened. However, when the system was cooled down with Nitrogen there was condensation on the outside of the vacuum jacket. We tracked that down to a leak from the O-ring seal at the top of the DR. This leak also explains why the He-4 background in the OVC was higher than the IVC. The leak was temporary fixed by redoing the Silicone sealant at the top flange. After the run we plan to replace the O-ring.