(Jordan, Travis, Jake, Owen, Gerardo)
After taking some RGA scans of CP1, and pushing nitrogen gas through the cryotrap (we injected nitrogen gas at the top sensor line for about 10 minutes), then we started the cooldown, or did we? First, we opened the "bypass" valve (fully open) to measure the number of turns to guesstimate a less than 10% open valve, per procedure E960127. Then we opened the bottom draw valve to release LN2 out of the dewar. We opened both valves around 2:00 pm, bottom draw fully open and bypass valve only 10%, but by 7:40 pm local time we terminated the cooldown, we didn't want to risk for something to go array overnight.
We did not see a sign that the cryotrap was getting nitrogen, nothing on the exhaust (the exhaust pressure remained the same), nothing on the cryotrap level (remained at zero), pressure internal to the cryotrap remain level, and the consumption remained level at the dewar for CP1. We are going to look more into this Thursday.
(Jordan V., Travis S., Gerardo M.)
CP1 cooldown re-start, apparently one or both of the valves did not respond as they should have, either the "bottom draw" and the "bypass" valves did not open yesterday, or one of them did not open, do not know which.
This morning I opened the valves in a different manner, and paid close attention to their behavior, the "bottom draw" valve made a small pop as I opened it, so I closed the valve and then opened it again, I had to do that about 3 different times, the last time there was no pop, it seems as if the valve was letting go of the sealing component, on the third attempt I was able to hear the LN2 rush thru. Same for the "bypass" valve, opened it with care and paid attention to the sounds it made, no pops noted, but to make sure I opened and closed the valve 3 times, never opening it more than 1/2 turn. Then set it the same way as yesterday, the guestimate of 10% open, about 0.8 turns. Then I was able to hear the nitrogen gas out of the exhaust line. Left CP1 and went to check on the progress via MEDM screens and plots. Soon we had the first numbers on the pump level % full, we started with a very tiny number but little by little the cryotrap started to fill. Because of the experience of with the above mentioned valves I decided to actuate early the LLCV, but only opening it up to 2%, eventually with time and two cell phones I was able to note that the LLCV was indeed actuating good. Soon the 85% came along and it was time to hand over the controls to the PID, which it did not have any issues, well 1 issue, the 15% output low limit was to high, the PID railed, so I lowered it to 10%, this number will be assessed on the upcoming days to see if we leave it or not. We left the RGA scanning during and post the cryotrap cooldown.
Vacuum pressure in CP1 has dropped and currently we are at 3.8x10-09 Torr, from about 4.0x10-08 Torr this morning.
The consumption of LN2 was good, the dewar dropped about 2.24% to fill the cryotrap.
The turbo pump continues to pump on the system and it will until we reach at least 1.0x10-09 Torr or better.