Chandra R., Kyle R.

Today I removed the turbo and leak detector equipment from IP1 that had been left connected but de-energized from last week's maintenance day .  I then installed a 1 1/2" O-ring valve in-series with IP1's 1 1/2" AMV pump port valve and evacuated the space between these two valves.  Chandra R., later, valved-in IP1 to the site vacuum volume and it seems to be working.

Next, I removed the existing turbo from IP6's 1 1/2" pump port and installed the one just removed from IP1 in its place.  The turbo which had been used during last week's leak checking of IP6 was suspected of confusing the test results by causing crosstalk permeation helium signal responses.  These were thought to be via that turbo's oversized and incorrect vent valve O-ring which has proven to be quite permeable to helium - even when only briefly exposed and in low concentrations - basically, a nuisance.  Also, that turbo had a KF inlet flange.  The turbo moved over from the IP1 setup has a CFF inlet and a minimally-permeable vent valve O-ring.  With new turbo + leak detector configuration up and running, Chandra R. and I then reapplied an audible flow of helium to re-test the new IP6 CFF joints.  This time there were no ambiguous signal responses (background < 5 e-9 torr*L/sec throughout testing). 

After letting the locally mounted turbo pump IP6 for an hour or so, I energized IP6's High Voltage.  82 mA - 40 mA - 11 mA - 2.6 mA etc...  I then closed the 1 1/2" AMV pump port valve, vented and spun down the turbo and shut down the leak detector.  IP6 will remain valved-out from the site vacuum volume but energized and pumping itself until "dry" enough to valve-in.