Maintenance for Helios

Due to vacuum jacket indium seal failure, vacuum jacket was removed. Indium wire changed to 0.055" but flange still leaked ( later on I discovered the main pumping stainless steel hose was leaking badly). Indium wire changed backed to 0.050" and the old ring and O-ring was added as a backup. Leak test ok at room and N2 temp. For simulating N2 temp, a pool of N2 was made on the top of vacuum jacket. BG=1E-8 (before zeroing)