kyle.ryan@LIGO.ORG - posted 15:00, Saturday 17 March 2018 - last comment - 15:52, Saturday 17 March 2018(41053)
Kyle on site doing Daily Check
I'll be at Y-mid checking in on the CP4 bake. I'll also "pop" in and look at the X-end and LVEA purge-air supplies. Gerardo M. has been notified.
I expect to be hear less than 90 minutes and will make a comment to this entry when I leave.
Comments related to this report
kyle.ryan@LIGO.ORG - 15:52, Saturday 17 March 2018 (41054)
Turbo pumping CP4 very close to overheating -> Valved-out turbo's UHP N2 purge and foreline pressure dropped from 2.5 x 10-2 Torr to 7.4 x 10-3 Torr. Also, stopped PLC PID bake, lowered the SETPOINT to 110C down from 130C.
We easily have enough heat now with the extra 10kW but are suffering from a significant Top to Bottom temperature gradient. This is a fundamental consequence of this initial setup and can't be easily addressed without stopping the current bake-out and then making significant modifications. Eliminating leaks between the insulating blankets would help some and can be done while bake is in progress. Also, use of the Regeneration System could also lessen the gradient but comes with its own added risks.
1555 hrs. local -> Kyle leaving site now.