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2023/05/04 (Thursday)

Previous Day

  • Lab in-personnel: Zach, Himangshu
1311 MC(Cernox) = 77.1 K, IVC = 3.0 mbar, G2/G1 = 546/590 mbar.
1315 Fill LN2 cold trap dewar
1316 IVC = 3.0 mbar, Start pumping out IVC with Scroll Pump. When pressure falls below 0.1 mbar switch to Turbo Pump.
1325 Turn on 3He pump and open V6 to 12.4%, re-establishing circulation like yesterday. G2/G1/P1 → 658/712/1.1 mbar and settled
1330 Close V12a speedivalve for 2 minutes to assess throughput. G1 falls at 64 mbar/min, good. Reopen V12a speedivalve
1333 Pump mixture to dump. Close V13a, open V3 (V9 already open), open V6 more in steps up to 30%
1350 G1 = 1.2 mbar, P1 = 0.090 mbar. Stop pumping mixture to dump. Close V12a+speedivalve, close V1, close V3, close V6
1355 V6 is fully closed, G2 = 720.6 mbar in the dump. Leave 3He pump on.
Throughput test procedure, Cold Trap 1:
  1. All mixture in dump, LN2 trap 1 cold, condenser & still valves open (3He pump on - optional)
  2. Open V9, V13a, V12a+speedivalve, V3. Wait for G1 to be close to G2 (within 100 mbar).
  3. Close V12a+speedivalve and V3, open V1
  4. monitor G1
1357 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 ~60 mbar, then rises. Throughput = 41.8 mbar/min.
1401 Open mixture to both sides of the fridge (V3) and cold LN2 Trap 1 (V12a+speedivalve).
1430 Turbo in IVC = 74 nbar, with the turbo valved out for a min, IVC = 1.2 ubar
1434 Pump IVC with Leak Detector, Turbo valved out, IVC = 300 pbarL/s
1445 Begin blowing out LN2 (following Blow Out Liquid Nitrogen). Main bath (G3) → 290 mbar+1atm
1450 IVC = 300 pbarL/s, MB = 288 mbar+1atm
1502 LD on IVC = 285 pbarL/s, MB = 303 mbar+1atm, IVC at 860 nbar
1512 LD on IVC = 270 pbarL/s, MB = 294 mbar+1atm, IVC at 860 nbar
1517 Swapped Bomb dewar.
1523 LD on IVC = 254 pbarL/s, MB = 179 mbar+1atm, IVC at 860 nbar
1533 LD on IVC = 240 pbarL/s, MB = 142 mbar+1atm, IVC at 860 nbar
1543 LD on IVC = 240 pbarL/s, MB = 142 mbar+1atm, IVC at 860 nbar
1544 Check output into bomb dewar, no more liquid, assume LN2 blowout is complete. G3 at 284 mbar (since i tried putting a stopper on the rubber hose). Close V2A, V5A, V4A, and V1A. Close the He gas supply and the valve on the gas line.
1550 Checking the rubber hose again it turns out there is still more to blow out, just that the pressure wasnt high enough, restart blowout
1554 LD on IVC = 240 pbarL/s, MB = 370 mbar+1atm, IVC at 860 nbar
1612 G3 dropping quickly, no liquid coming out of the hose, LN2 blowout must be complete. Close V2A, V5A, V4A, and V1A. Close the He gas supply and the valve on the gas line.
1619 Turn off 3He pump, we'll leave it off like last time.
1620 Wait for the rubber hose to warm up to remove the tubing from the transfer stick, and then plug the transfer stick.
1623 Start pumping out main bath with scroll pump.
1633 Open scroll pump fully, P2 falls in range soon after
1640 P2 = 0.95 mbar, stop pumping on main bath by closing the scroll pump valve and turning off the scroll pump.
1645 Pressurize MB with helium to 94 mbar above 1 atm.
1647 Isolate MB by closing V1a. Pump out line to the G3 volume (including 2a and 5a) with Scroll Pump. Isolate pump (and close 2a, 5a), then open 1K Pot speedivalve to check pressure: didn't see the mechanical gauge move much, P2 went to 90 mbar. Then pump out 1K Pot (needle valve closed) with Scroll Pump to 0.034 mbar on P2. Then close 1K Pot speedivalve and V4a. Open V1a again to monitor bath pressure, G3 = 63.8 mbar.
1654 Close and turn off leak checker. IVC is at 1.9 ubar. Let 63 μbar He exchange gas into IVC (very carefully).
1707 Begin initial LHe transfer @ MB = -1.0%
1754 MC(Cernox)/Sorb/1K Pot = 76.78/110/6.99 K, IVC = 1.6 μbar, G1(fridge) = 514 mbar. G3(MB) = 436 mbar+1atm, MB = 10%
1810 MC(Cernox)/Sorb/1K Pot = 76.5/104/6.99 K, IVC = 1.2 μbar, G1(fridge) = 463 mbar. G3(MB) = 368 mbar+1atm, MB = 40%
1820 MC(Cernox)/Sorb/1K Pot = 76.35/99/6.99 K, IVC = 1.2 μbar, G1(fridge) = 458 mbar. G3(MB) = 410 mbar+1atm, MB = 66%
1830 Pausing the transfer now as the level started going low again even after inserting the stick all the way into the He dewar. I am afraid there will be more boil off during the transfer that we are out of LHe without getting too cold. So, we will keep this LHe and redo another transfer tomorrow.
2130 Current rate of temp fall is 7 K/hr. At 9:30 pm, it is at 66 K, if rate remain constant, it might get to 10K at 5:30 am tomorrow.
2239 MC at 41 K, open turbo to IVC. IVC pressure hit 1.9e-4 mbar after about a minute.
2243 Close V1a. MB = 20.2%
1341 Electrical check of ZC-70+interposer after connecting to Stripline 41 on Tower Face 5
Cooldown checkout sheet (rev C SQUET)
Detector: S104 Stripline 41
SC: none 77 K 77 K
Face: 5 Date 05/04/2023
SQUET: ZC-70 Cable 2
Signal Pos. lead Gnd lead Nominal Actual Chassis
(Gnd lead)
Nominal:
< 0.1 nS
SQUID bias A/Ret 4 20 3 - 5 k — k OK
SQUID bias B/Ret 19 34 1.646 k OK
SQUID bias C/Ret 8 24 1.758 k OK
SQUID bias D/Ret 23 39 1.985 k OK
Feedback A/Ret 37 21 15 - 25 k 14.59 k OK
Feedback B/Ret 2 18 9.15 k OK
Feedback C/Ret 41 25 13.82 k OK
Feedback D/Ret 22 6 16.91 k OK
QET A/Ret 3 1, 13, 14, 17, 32 60 - 80 OL,68.8,OL, OL, OL OK
QET B/Ret 35 29, 33, 47, 48 40.7, 41, OL, OL OK
QET C/Ret 7 5, 9, 10, 28 45.4, 44.6, OL, OL OK
QET D/Ret 38 36, 40, 43, 44 41.8, 42.5, OL, OL OK
QET A/QET B 3 35 1000-3000 16.41 kohm
QET A/QET C 3 7 16.42 kohm
QET A/QET D 3 38 OL
QET B/QET C 35 7 219
QET B/QET D 35 38 OL
QET C/QET D 7 38 OL
LED 1 chassis 42 1.0 - 1.1 V 1.383
LED 2 chassis 26 1.856
Motor Coil 1 pBr3 pBr4 34
Motor Coil 2 pCr3 pCr4 6.56 k
Near Endstop pAr3 chassis 7.96 k
Far Endstop pAr4 chassis 32.26 k
Thermometer ROX pAr1 pDr4 1.216 k
1441 Electrical check of ZC-13 after connecting to Stripline 43 on Tower Face 2
Cooldown checkout sheet (rev C SQUET)
Detector: S104 Stripline 43
SC: none 77 K 77 K
Face: 2 Date 5/4/2023
SQUET: ZC-13 Cable 3
Signal Pos. lead Gnd lead Nominal Actual Chassis
(Gnd lead)
Nominal:
< 0.1 nS
SQUID bias A/Ret 4 20 3 - 5 k 1.727 k OK
SQUID bias B/Ret 19 34 1.817 k OK
SQUID bias C/Ret 8 24 — k OK
SQUID bias D/Ret 23 39 1.884 k OK
Feedback A/Ret 37 21 15 - 25 k 7.45 k OK
Feedback B/Ret 2 18 7.98 k OK
Feedback C/Ret 41 25 — k OK
Feedback D/Ret 22 6 8.39 k OK
QET A/Ret 3 1, 13, 14, 17, 32 60 - 80 73.7, 38.2, 34.2, 34.4, 42.5 OK
QET B/Ret 35 29, 33, 47, 48 34.3, 34.5, 59.8, 34.4 OK
QET C/Ret 7 5, 9, 10, 28 39, 37.5, 26.4, 34.7 OK
QET D/Ret 38 36, 40, 43, 44 50.5, 38.7, 37.7, 38.1 OK
QET A/QET B 3 35 1000-3000 OL
QET A/QET C 3 7 OL
QET A/QET D 3 38 OL
QET B/QET C 35 7 OL
QET B/QET D 35 38 OL
QET C/QET D 7 38 OL
1248 Electrical check of ZC-39 after connecting to Stripline 48 on Tower Face 3
Note: This SQUET need to slanted to make QET B working, seems to be affected by the angle between stripline head connector with the SQUET
Detector: S104 Stripline 48
SC: none 77 K 77 K
Face: 3 Date 5/04/2023
SQUET: ZC-39 Cable 1
Signal Pos. lead Gnd lead Nominal Actual Chassis
(Gnd lead)
Nominal:
< 0.1 nS
SQUID bias A/Ret 4 20 3 - 5 k 1.632 k OK
SQUID bias B/Ret 19 34 1.493 k OK
SQUID bias C/Ret 8 24 — k OK
SQUID bias D/Ret 23 39 — k OK
Feedback A/Ret 37 21 15 - 25 k 8.82 k OK
Feedback B/Ret 2 18 8.24 k OK
Feedback C/Ret 41 25 9.17 k OK
Feedback D/Ret 22 6 6.39 k OK
QET A/Ret 3 1, 13, 14, 17, 32 60 - 80 74.1, 34.5, 29.4, 29.7, 40.6 OK
QET B/Ret 35 29, 33, 47, 48 33.2, 33.4, 34.6, 33.4 OK
QET C/Ret 7 5, 9, 10, 28 34.1, 32.7, 23.3, 33.3 OK
QET D/Ret 38 36, 40, 43, 44 30, 30.3, 29.3, 29.6 OK
QET A/QET B 3 35 1000-3000 1735
QET A/QET C 3 7 2535
QET A/QET D 3 38 2166
QET B/QET C 35 7 2626
QET B/QET D 35 38 2243
QET C/QET D 7 38 1079

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