1 Stony Brook Update Stretching your LEGS T.K. Hemmick for the tent crew

2 Some struggles since last week Recirculation pump on LEGs failed again. –Overtemp stops pump. –Cooling fan replacement was improper. –Changed out for “overkill” version. –Runs quite cool now. Set up flow system through HBD bypass. –Trouble…Pressure drop in the lines was to severe. –Order larger return pipe Thursday: Purchasing didn’t get order out until Friday. Company delayed shipping. Parts did NOT arrive Monday. Decided to “use the tools available”.

3 Modify pressure controller location: Lines in red had large pressure drop under nominal conditions since the flow is high (2 lpm). Moving the point of the pressure controller (even with this line) fixes the problem since the PC is a low flow device. Pump Mass Flow Analyzer HBD Vent Pressure Controller Vent

4 New Configuration: New line may be long, however since pressure controller draws only a small flow, the pressure in the HBD is properly regulated at high flow. The throttled pump on out PC output serves to increase the capacity of the PC at pressures near room pressure and makes a HUGE improvement in the stability of the system. Pump Mass Flow Analyzer HBD Vent Pressure Controller Pump

5 Glovebox regeneration started. The regen cycle of the glovebox started Monday evening and will finish Tuesday. This was likely nearly ready to run out and is good timing. When the HBD was placed on LEGS –the water started at 22 ppm (same as glovebox which was rising) –dropped to 17.4 ppm after an hour. Bad news: WS1 bottom GEM had dead short on final test. We plan to test the rest of the detector and if no other flaws occur, we’ll replace this one resistor.