1. 1 Stony Brook Update Leaks in LEGS and HBD West T.K. Hemmick for the Tent Crew

2. 2 LEGS Gas System: Extensive Leak Diagnostics show: –With HBD bypassed (and doing leak-down tests), one can vary fresh gas input and recirculation and thereby vary the relative pressures in the system while watching O 2 –O 2 rate STRONG function of pressures throughout system, but only monotonic with two pressures: return line: 0-2 Torr overpressure recirculation pump head pressure 5-7 psi. Likely return line, but can’t pinpoint running N 2 Argon run through whole system over weekend. Today: –0.7 lpm (pass-through to maximize return line pressure) –O 2 = 77 ppm –H 2 O = 49 ppm System now fully purged with Argon, ready to leak test to poinpoint leak

3. 3 HBD Leakdown Tests Two tests: –Inside vs Outside air (sys error?) –Inside vs sealed volume. Same result: ~1 torr loss in 150 minutes. For DCH this would be WONDERFUL!!! Is it OK for HBD???

4. 4 Tom’s Recommendation: Time is an issue. I believe that we should remove the GEMs from this HBD and work in parallel to: –Put new CsI on these. –Finish HBD East first. –Leak chase LEGS. –Leak chase HBD West. –Then re-equip HBD West with new GEMS from WIS.