2022/12/12 Monday)

Status	Run 76 ending
Setup	DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe removed from lab. NaI scan in progress
	Warming up. Mixture in dump. Mixture removed from LN2 Trap 1 but it still has contaminants. Some He exchange gas in cryostat vacuum jacket and IVC.
1110	Begin disassembling walls of lead/poly shield
1120	Close MB recovery valve (above the coiled copper pipe)
1120	MC(Cernox) = 263.54 K, 1.1 K/hr. Implies warming tau of 26.5 hours, should reach dew point (around 34 F) at Dec 12 22:57
1150	All lead removed from N and S walls of shield
1200	Shut down NaI array, with remote help from Anthony and Kitty. Summary of steps:

Logon to NaI PC (VGA output - login cdms / [redacted]
open CAEN GECO software
find IP address for CAEN HV module in bookmarked NaI manual on Firefox
login “admin”, password “[redacted]”
Find column “Pw” (power), set all HV to “off”. (Can use space bar and arrows.) They will ramp down at a preprogrammed rate
Switch CAEN unit off physically with key switch

1230	Unplug HV and signal cables from all NaI panels, carefully. Pull cables out to free them from shield wall.
1350	Start removing PMT bases from NaI paddles (black part separates from stainless steel, can use a screwdriver to gently wedge them loose). Start removing boron socks from NaI stack too. Removed top front horizontal piece from rack first to make sock removal easier.
1700	Removing NaI detectors from rack and placing them in their foam-cushioned boxes in the LIGO lab closet. First remove the top left and right pieces from rack, as well as 4 small rounded nuts at the top. Then lift out the first four detectors, careful to support them from the main NaI piece and not the phototube end. The fifth, just above the pieces separating the 1-5 substack from the 6-10 substack, was kinda stuck - eventually got it out. Then removed the separating section and 4 more small rounded nuts. Etc all the way down.
1730	MC(Cernox) = 269.94 K, 1 K/hr. Implies warming tau of 24.5 hours, should reach dew point (around 34 F) at Dec 12 22:25
1745	Check pressure in cryostat vacuum jacket: 0.14 mbar. Slightly higher than where we're supposed to start pumping with the Turbo, but I went ahead and opened the Turbo valve slowly till it got below 0.1 mbar, then opened all the way. We'll pump overnight so we don't have to worry about it later - hopefully the fridge will be warm enough to open by the time we get to it later tomorrow.