aLIGO LHO Logbook

LHO VE

chandra.romel@LIGO.ORG - posted 10:26, Thursday 25 August 2016 - last comment - 15:49, Thursday 25 August 2016(29300)

CP4 experiment

Running a Worden experiment:

-CP4 at 88% full
-Set LLCV to nominal in manual mode (41% open)
-Increase LLCV by 5% (43% open) and leave it at this value
-Monitor increase in fill
-Allow fill to exceed 100% and monitor exhaust flow meter (expect a sharp increase in flow when liquid starts to hit warm exhaust)
-After this sharp increase, reduce LLCV by 10% to below nominal (<41%)
-Hope that no LN2 reaches the flow meter this time (when flow approaches 100% I will monitor while sitting next to exhaust to be ready to open bypass exhaust valve and remove flow meter with LN2 gloves on)

**THIS WILL GENERATE CP4 ALARM ON PUMP LEVEL**

Comments related to this report

chandra.romel@LIGO.ORG - 10:29, Thursday 25 August 2016 (29301)

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Note:  this is done with Dewar at 39.6% full

chandra.romel@LIGO.ORG - 13:53, Thursday 25 August 2016 (29306)

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I increased LLCV to 45% (10% increase from nominal) to speed things up. 5% LLCV increase is about 1% fill increase every 40 min.

chandra.romel@LIGO.ORG - 15:49, Thursday 25 August 2016 (29317)

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Taking too long to reach critical point (>100% full), so I'm terminating this experiment before alarms start (>98% full), and will restart early tomorrow at 90% full set point.