2022/10/01 (Saturday)
- Lab in-personnel: Matt
| Status | Run 76 in progress |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side2-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC50(3)/DCRC55(1), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe source behind lead wall on West side of lead/poly shield. |
| NaI trigger window: 7.6-11.2 MeV | |
| Eleventh 5K pumpout yesterday. Turbopumping IVC overnight. | |
| 1615 | MC/1KPot/Sorb = 5.40/6.67/8.5 K. G1(fridge) = 545 mbar |
| 1615 | Turbo on IVC = 1.4 nbar. With Turbo valved out for 1 minute IVC = 14 nbar. |
| 1615 | Close IVC valves on top of fridge |
| 1620 | Turn on 4He pump. Open Recovery valve to 4He pump. Pump out line to 1K pot (speedivalve closed). Check pressure in 1K Pot (with V4a open, 4He pump inlet valve closed). 1K Pot = 0.24 bar on mechanical gauge. |
| 1620 | Pump out 1K Pot in stages, alternating 1K Pot Speedivalve and V4a, opening V4a in brief spurts to keep 4He pump pressure low (below 5 mbar). |
| 1625 | Start pumping 1K Pot continuously |
| 1630 | MC/1KPot/Sorb = 5.39/3.25/4.1 K |
| 1630 | 1K Pot = 0° / 3.25 K / 3.2 mbar |
| 1630 | Open 1K Pot needle valve → 15°. 1K Pot → 3.06 K / 6.0 mbar |
| MC temperature falling | |
| 1635 | Fill LN2 cold trap bath |
| 1635 | MC/Coldplate/Still/Sorb = 3.43/“4.91”/“3.43”/4.0 K |
| 1640 | Open 1K Pot needle valve → 30°. 1K Pot → 2.89 K / 7.5 mbar |
| 1640 | MC = 3.36 K. G1(fridge) = 422 mbar |
| 1645 | Open 1K Pot needle valve → 45°. 1K Pot → 2.60 K / 11 mbar |
| 1645 | MC = 3.28 K. G1(fridge) = 389 mbar |
| 1645 | Plug in DCRCs 1&3 |
| 1745 | MC = 2.24 K |
|---|---|
| 1745 | Close V3 and V9, leaving 64 mbar mixture in dump (G2) |
| 1745 | Turn on 3He pump. G1(condenser) 64 → 90 mbar. |
| 1750 | Start circulation through Trap 1. V6 → 12.6%. Condenser peaks at 303 mbar. MC(H35) → 1.6 K. |
| 1755 | V6 → 13.0%. Condenser(G1) peaks at 330 mbar. MC(H35) → 1.35 K. Still(P1) → 30 mbar. |
| 1800 | V6 → 13.4%. Condenser(G1) peaks at 285 mbar. MC(H35) → 1.25 K. Still(P1) → 10 mbar. |
| MC temperature wiggles as it passes through the Al Tc | |
| 1805 | V6 → 13.8%. Condenser(G1) peaks at 255 mbar. MC(H35) → 0.84 K. Still(P1) → 3.0 mbar. |
| 1815 | V6 → 14.4%. Condenser(G1) peaks at 188 mbar. MC(H35) → 1.7 K. Still(P1) → 0.62 mbar. |
| 1820 | V6 → 15.0%. Condenser(G1) peaks at 178 mbar. MC(H35) → 0.72 K. Still(P1) → 0.20 mbar. |
| 1835 | V6 → 100%. Condenser(G1) peaks at 152 mbar. MC(H35) → 52 mK. Still(P1) → 0.15 mbar. |
| 1850 | Since the 1K Pot is running a bit low, spent an hour opening V14 in bursts to let the rest of the mix out of the dump and into circulation, keeping the Still pressure below 40 mbar. Repeated about 20 times before leaving it open. Little peaks in the condenser pressure and MC temperature. |
| 1940 | 1K Pot rises from 1.56K/8.5mbar → 1.59K/12±1mbar, good. |
| 1950 | Still = 0.90 mbar. Close V14. Still → 0.11 mbar. MC → 29.1 mK. |
| 2100 | MC = 28.3 mK. Still = 1.12 K / 0.11 mbar. G1/G2 = 120/108 mbar. 1K Pot = 1.59 K / 12±1 mbar. |
| 2255 | Check phonon channels. Get all but DCRC3pA back to -0.80 baselines. Adjust DCRC3pA offset to get its baseline close to -0.80V too. |
| MC rises to 29.3 mK after turning on DAQ programs. | |
| 2256 | Dial HV up to -109.25V nominal, -107.2V actual, for 15% prebias (using RootSequencer) |
| 2301 | Dial HV down to -95V nominal, -92.9V actual |
| 2308 | Vdet is 89%. Adjust HV down to -94V nominal. |
| 2310 | HV = -91.8 V, Vtest = -21.2 mV, Ileak = -23.3 uA, Vdet = -82.5 V (90%). |
| Check triggering. Looks like the low DCRC1pA threshold of 2 still works fine, plenty of pulses showing up in the right place. | |
| 2314 | Start -82.5 V PuBe data series ## min long, SiHV-triggered with 1000 initial randoms, 5 Hz in-run randoms, trigger on DCRC1pA threshold 2. Start series with the Start Button |
| 2335 | HV = -91.8 V, Vtest = -21.1 mV, Ileak = -23.2 uA, Vdet = -82.6 V (90%). |