2024/08/16 (Friday)

Status	Run 81 beginning, LN2 transfer yesterday, mixture in dump.

XXXX	MC(Cernox) = 77.41 K, Sorb = – K, G2/G1/P1 (circulation) = 510/490/(maxout) mbar
XXXX	IVC = 2.2 mbar, Start pumping out IVC with Scroll Pump. When pressure falls below 0.1 mbar switch to Turbo Pump.
—	Not yet filled LN2 cold trap dewar
XXXX	Take electrical checks on the three cables
XXXX	Turn on 3He pump and open V2 to 180+ deg, reestablishing circulation like yesterday. G2/G1/P1 → 590/600/0.5 mbar and settle
XXXX	Close V3 for 2 minutes to assess throughput. G1 falls at ~50 mbar/min. Reopen V3
XXXX	Pump mixture to dump. Close V8, open V5 slightly (V9 already open), open V2 more in steps up to 30%
XXXX	G1 = ~0 mbar. Stop pumping mixture to dump. Close V3, close V1, close V5, close V2
1228	V2 is fully closed, close V9, leaving 620 mbar in the dump. Leave 3He pump off.

	Throughput test procedure, Cold Trap 1:

All mixture in dump, LN2 trap 1 is cold, condenser & still valves open (3He pump on - optional)
Open V9, V8, V3, V5. Wait for G1 to be close to G2 (within 100 mbar).
Close V3 and V5, open V1
monitor G1

1230	Perform mixture throughput test at MC = 77 K using above procedure with 3He pump on. Let G1 rise to ~500 mbar before Step 3, then it falls to ~50 mbar, then rises. Throughput = ~25 mbar/min.
1232	Open mixture to both sides of the fridge (V5) and cold LN2 Trap 1 (V3).
1235	Pump mixture to dump
1240	Start cryocleaning again, will cryoclean during LN2 blowout
1355	Turbo on IVC = 63 nbar, with turbo valved out for a min IVC = 140 nbar
1356	Pump IVC with Leak Detector, IVC = 3600 pbarL/s, much too high to see leaks
	Going to blow out and do LHe transfer tomorrow
1310	Perform leak test with LN2 in MB, blow helium through transfer tube (make sure tube is pressed against insert in MB). See no leaks, but leak detector level is too high, cant trust it
1310	Fill MB with rest of LN2