2021/03/09 (Tuesday)

Lab in-person: Derek
Virtual partner: Matt

Status	Run 74 in progress. Doing a partial warmup to recheck continuity to Side2. V6 closed, no circulation. 1K Pot is on. 3He pump still running.
	Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/nothing → DCRC50(3)/~~55(1)~~breakout box. No lead/poly shield.
0915	Tower = 2.04 K. MC heater is off. Condenser(G1) = 54 mK. These were steady overnight with the heater off, slowly decreasing.
1100	Derek enters lab.
1101	Side2/qI = 0.08 ± 0.01 ns (Fluke multimeter)
1102	Tower/MC/Coldplate = 1.77/2.03/2.67 K, Still = 2.13 K / 1000 mbar / 0 mW, G1/G2 = 41.3/38.1 mbar, 1K Pot = 1.66 K / 32±2 mbar.
1103	MC Cernox = 1.85 K
1108	MB = 29.3%
	Let's stop the 1K Pot
1115	Close 1K Pot needle valve. 1K Pot → 1.47 K / 4 mbar.
1120	Close 1K Pot speedivalve. 1K Pot → 1.8 K and rising
1120	Turn on MC heater → 20 mW
1135	Tower/1K Pot = 2.4/2.3 K, Condenser = 60 mbar. All are rising.
1155	Tower/1K Pot = 3.12/3.13 K, Condenser = 348 mbar.
1200	Tower = 3.16, Side2/qI = 0.20 nS Tower = 3.26, Side2/qI = 0.30 nS
1205	Tower = 3.32, Side2/qI = 0.38 nS. qI/qO = 6.0 nS
	after switching back to the Side2/qI connection, conductance had dropped a bit, to 0.2 nS, but rising again.
1210	Tower = 3.45, Side2/qI = 0.46 nS. Tower = 3.48, Side2/qI = 0.60 nS. qI/qO = 5.92 nS
1215	Turn off MC heater. Let's cool back down.
1215	Condenser = 637 mbar
1255	Pumping out the 1K Pot in steps for the last 40 minutes. Alternating opening speedivalve and V4a, opening V4a in short bursts to keep pressure below ~ 10 mbar. Repeat this about 30 times. Then leave speedivalve open and open V4a in bursts several times, keeping pressure <~ 50 mbar. Finally leave speedivalve and V4a open.
1255	1K Pot = 1.53 K / 6.5 mbar. Tower = 2.5 K and falling. Condenser = 254 mbar and falling.
1300	Open 1K Pot needle valve → 10°. 1K Pot → 1.53 K / 6.5 mbar. Open 1K Pot needle valve → 20°. 1K Pot → 1.54 K / 7.0 mbar.
1305	Open 1K Pot needle valve → 30°. 1K Pot → 1.56 K / 8.5 mbar. Open 1K Pot needle valve → 40°. 1K Pot → 1.58 K / 11 mbar. Open 1K Pot needle valve → 45°. 1K Pot → 1.58 K / 11 mbar.
1310	1K Pot = 1.58 K / 11 mbar. Tower/MC(H35) = 2.19/2.53 K, G1 (fridge) = 146 mbar
1310	1K Pot spikes, looks like the lambda-point spike. Settles around 1.70 K / 50±5 mbar
1315	Derek exits lab
1420	1K Pot = 1.70 K / 50±5 mbar. Tower = 2.17 K, G1 (fridge) = 70 mbar. Tower is cooling very slowly. Fridge pressure is settling.
	Let's restart circulation.
1425	Turn on 3He pump. G1 (fridge) settles at 83 mbar.
1430	Start circulation through Trap 2. V6 → 11.6%. Not seeing any increase in fridge pressure. Maybe the V6 setting has shifted again and this setting is too low to be open at all.
1435	V6 → 12.0%. Still no increase in pressure. V6 → 12.4%. Still nothing.
1440	V6 → 12.8%. Condenser peaks at 77.6 mbar. V6 → 13.2%. Condenser peaks at 470 mbar. 1K Pot pressure spikes then settles. Tower drops to 1.81 K.
1455	V6 → 13.4%. Condenser peaks at 417 mbar. Still → 60 mbar. Tower → 1.51 K.
1505	V6 → 13.8%. Condenser peaks at 530 mbar. Still → 10 mbar. Tower → 1.43 K.
1520	Condenser = 400 mbar, Still = 4.0 mbar, Tower = 1.18 K
1520	V6 → 14.0%. No increase in condenser pressure. Still → 3.8 mbar. Tower → 1.11 K.
1530	V6 → 14.4%. Condenser peaks at 353 mbar. Still → 2.6 mbar. Tower → 1.01 K.
1540	V6 → 15.0%. Condenser peaks at 387 mbar. Still → 1.6 mbar. Tower → 0.84 K.
1615	V6 → 100%. Condenser peaks at 415 mbar. Still → 0.24 mbar. Tower → 0.71 K.
1645	Tower = 176 mK, Still = 0.150 mbar, G1/G2 = 309/290 mbar.
1730	Tower = 121 mK, Still = 0.130 mbar, G1/G2 = 269/254 mbar.

1430	Zach arrives at lab.
1448	Begin LHe transfer @ MB = 23.2%
1509	Finished filling LN2 cold trap dewar.
1524	End LHe transfer @ MB = 91.2%

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