2019/11/06 (Wednesday)
| Status: Initial LHe transfer yesterday. 2nd or 3rd attempted cooldown for Run 71 (depending on how you count). | |
| 0835 | MC(H35)/Sorb/1K Pot = 4.78/8.5/6.70 K. All creeping upward overnight. G1(fridge) = 557.7 mbar. |
| 0835 | Tower = 4.76 K. (Coldplate/Still = 17.1/12.1 K. These clearly don't have good calibrations here.) |
| 0840 | MB = 66.7% / 138 mbar |
| 0840 | Motor A/B = 21.3/13.8 Ω. These are superconducting now. Backward & Forward endstops to ground are both less than 1 nS. |
| 0845 | Turbo on IVC = 5.4 nbar. With turbo valved out for a minute, IVC = 74 nbar. Open Turbo valve again, we'll keep pumping on IVC. |
| Turbo on IVC not as low as the last successful cooldown, although that was after a long time pumping out after multiple blockages. Better to compare to Run 69 - also not as low as that time. | |
| 0850 | Fill LN2 cold trap bath from bomb Dewar. (Bomb Dewar empty now.) |
| 0905 | Pump out line leading to 1K Pot with scroll pump |
| 0905 | Switch over to 4He pump. Change pump exhaust to recovery and open valve to recovery lines. |
| 0910 | Check pressure in 1K Pot by closing V4A and opening 1K Pot speedivalve: the mechanical gauge goes up about 0.33 bar This brought the 1K Pot temp down to 4.6 K |
| 0920 | Pump out 1K Pot in steps, alternating between V4a and the 1K Pot speedivalve. After 10 iterations get pot down to around 0.13 bar. Then leave 4He pump pumping on pot continuously. |
| 0925 | MC(H35)/Sorb = 4.75/4.0 K. MC falling a little, Sorb fell a lot. |
| 0925 | 1K Pot = 3.14 K / 2.6 mbar. |
| 0925 | Open 1K Pot needle valve → 10°. 1K Pot → 2.8 K / 8.5 mbar. MC temperature falling faster. Fridge pressure starts to fall. Open 1K Pot needle valve → 20°. 1K Pot → 2.5 K / 16.0 mbar. MC falling fast. |
| 0930 | MC(H35)/Sorb = 3.37/4.0 K, Fridge(G1) = 458 mbar. Open 1K Pot needle valve → 30°. 1K Pot → 2.0 K / 40.0 mbar Open 1K Pot needle valve → 40°. 1K Pot pressure (P2) spikes to 450 mbar, then starts falling slowly. |
| 0935 | MC(H35)/Sorb = 3.09/4.0 K, Fridge(G1) = 338 mbar. MC and Fridge falling pretty fast. (Sorb may be at minimum of range.) 1K Pot = 1.79 K / 400 mbar |
| 0940 | MC(H35) = 2.70 K, Fridge(G1) = 198 mbar. 1K Pot = 1.75 K / 130 mbar |
| 0955 | MC reaches about 2.1 K and 1K Pot spikes. 1K Pot had fallen to 1.62 K / 17 mbar, then shot up to around 1.8 K / 300 mbar and oscillating. |
| 1010 | MC(H35) = 2.10 K, Fridge(G1) = 62 mbar. 1K Pot = 1.76 K / 350±50 mbar. MC temperature and Fridge pressure are pretty flat. |
| 1020 | MC was hanging at 2.1 K (LHe lambda point) but now starts cooling again. |
| 1025 | MC(H35) = 2.02 K, Fridge(G1) = 62 mbar. 1K Pot = 1.75 K / 300±50 mbar. |
| G2 is lower, at 43.4 mbar. | |
| 1030 | Close V3 and V9, leaving 43 mbar (G2) in the dump. |
| 1030 | Start circulation through Trap 2. V6 → 12.8%. Condenser peaks at 100 mbar. Tower falls to 1.87 K. 1K Pot gets a little more stable: 1.75 K / 270±10 mbar. |
| 1040 | MC(H35) = 1.88 K, G1/G2 = 64/50 mbar, 1K Pot = 1.75 K / 270±10 mbar. |
| 1040 | V6 → 13.2%. Condenser peaks at 115 mbar. 1K Pot spikes and recovers. MC(H35) → 1.78 K |
| 1050 | MC(H35) = 1.69 K, G1/G2 = 101/98 mbar, 1K Pot = 1.75 K / 270±30 mbar. |
| 1050 | V6 → 13.4%. Condenser peaks at 127 mbar. 1K Pot spikes and recovers. MC(H35) → 1.54 K. Still pressure remains offscale. |
| 1100 | MC(H35) = 1.54 K, G1/G2 = 113/113 mbar, 1K Pot = 1.75 K / 270±30 mbar. |
| 1100 | V6 → 13.6%. Condenser peaks at 134 mbar. Still pressure falls into range. MC(H35) → 1.36 K. |
| 1110 | MC(H35)/Tower = 1.38/1.48 K, G1/G2 = 123/122 mbar, Still = 70 mbar, 1K Pot = 1.75 K / 240±30 mbar. |
| uptick in fridge pressures and MC temperature, let these settle… | |
| 1115 | MC(H35) = 1.38 K, G1/G2 = 119/118 mbar, Still = 75 mbar, 1K Pot = 1.75 K / 230±30 mbar. Some oscillating in fridge pressures, MC temperature |
| 1120 | V6 → 14.0%. Condenser peaks at 155 mbar. Still →15 mbar. MC(H35) → 1.29 K. |
| 1125 | MC(H35) = 1.12 K, G1/G2 = 122/116 mbar, Still = 6.0 mbar, 1K Pot = 1.75 K / 250±20 mbar. |
| 1125 | V6 → 14.4%. Condenser peaks around 135 mbar. Still →4.5 mbar. MC(H35) → 1.1 K. |
| 1130 | MC was hanging around 1.1-1.2 K but now falling again. |
| 1140 | MC(H35) = 0.63 K, G1/G2 = 132/126 mbar, Still = 4.0 mbar, 1K Pot = 1.75 K / 230±20 mbar. Condenser and MC falling steadily. |
| 1140 | V6 → 15.0%. Condenser keeps falling. Still →2.5 mbar. MC(H35) → 0.5 K. |
| 1155 | MC(H35)/Tower = 0.32/0.32 K, G1/G2 = 117/111 mbar, Still = 2.0 mbar, 1K Pot = 1.74 K / 220±20 mbar. |
| 1155 | V6 → 100%. Still → 0.34 mbar. Tower → 0.28 K |
| 1210 | Tower = 89 mK, G1/G2 = 100/94 mbar, Still = 0.19 mbar. Coldplate = 205 mK, Still = 1.43 K |
| 1220 | Tower = 55.8 mK and flat. G1/G2 = 79/72 mbar, settling. Still = 0.15 mbar, settling. 1K Pot = 1.75 K / 210±15 mbar. |
| 1220 | Open V14 to let the remaining mix out of the dump and into circulation. P1(Still) rises off scale, falls again after a 20 seconds or so. Condenser peaks at 120 mbar. Tower → 100 mK and rising. 1K Pot pressure spikes and recovers. |
| 1305 | Tower = 47.0 mK, slowly falling. G1/G2 = 77/69 mbar, flat. Still = 0.40 mbar. 1K Pot = 1.74 K / 190±15 mbar. |
| 1305 | Close V14 |
| 1330 | Tower/MC/Coldplate = 46.2/31.5/187 mK, Still = 1.40±0.02 K / 0.150 mbar, G1/G2 = 77/70 mbar, 1K Pot = 1.74 K / 190±15 mbar. |
| 1355 | Plug cables into DCRCs: DIB1/2/4 → 3.2 MHz filters → cable 1/2/3 → gender changer 1/2/3 → movable source controller/board with external Feedback resistor/nothing → DCRC55(1)/DCRC33(2)/DCRC50(3) |
| 1355 | Power on DCRCs. Tower spikes 46→49 mK then settles back to 46.5 mK. |
| 1405 | Configure DCRCs in ODB and try turning on DAQ programs (dcrcdriver, towerfe, triggerfe) |
| note - we kinda forgot standard trace lengths and prepulse lengths for charge/phonon… correct standard is phonon/charge = 8192/16384, 500/500. For 3.2768 ms traces, 400 us prepulse. (Maybe don't really need such long charge traces) | |
| 1425 | Notice that the MIDAS runs keep stopping and restarting every minute. Apparently this is because in the ODB, Logger/Run Duration has been set to 60 - it's normally set to 0. |
| 1430 | Try turning on 15V Power on DCRC1. But also notice that it's on on DCRC2 and that DCRC2 is set to Rev 3.1 (wrong). Tower temperature rises to 55 mK, I'm not sure what exactly did it. Turn off 15V powers. Tower cooling again. |
| 1430 | Turn 15V power on on DCRC1 (DIB1). Tower temperature rises to 57 mK or so |
| 1430 | Turn 15V power on on DCRC2 (DIB2). Tower rises a little more but not much more than before, approaching 58 mK |
| 1435 | Apply +4/-4 V bias to DCRC1/2 which is DIB 1/2 which is Side1/2. |
| 1440 | Seeing charge pulses in DCRC2! Railed charge channels on DCRC1. We saw some noise in these before turning on the 15V power, now railed. Played with AmpOffset in ODB but can't unrail. Note that AmpOffset does have an effect on DCRC2 channels. |
| 1445 | Is DCRC1 in a “bad state”? Temperature high at 59 mK and problems with the channels. Let's try a power cycle. Turn off DAQ programs, power down DCRCs. Tower temperature falling. |
| 1450 | Tower has cooled to 47 mK. Power on DCRCs again. Temperature rises a bit. Start DAQ programs. Temperature settling, not nearly as high as before - 48 mK and falling. |
| 1455 | Now seeing pulse in all four charge channels! Nice. |
| 1500 | Try zapping SQUIDs using DCRC_UI tool. Doesn't work, throws an error message. |
| 1500 | Go to /home/hep/cdmssoft/scdmsDAQ/MidasDAQ/online/scripts/pysequencer in a browser. Here there is a script ZAP.py which the tool uses… Try python ZAP.py -h. This also throws an error… |
| 1505 | Tower = 46.6 mK, flat |
| 1510 | Try making a ZAP sequence: python ZAP.py –dcrc 1,2,3 –chan A,B,C,D –onoff 2,30 –iter 2 > ../../sequencer/testzap.msl |
| 1515 | ZAP all SQUIDs using above sequence. See Still pressure and Tower temperature spike, seems to work. Tower temperature goes pretty high, over 70 mK, then falls |
| 1526 | Look up SQUID and Phonon settings from an ancient odb from run 56 (run02835.odb) |
[/Equipment/Tower01/Settings/DCRC1/Phonon] VGAGain (multiplicative factor) = FLOAT[4] : [0] 5 [1] 5 [2] 5 [3] 5 LockpointAdjust (mV) = FLOAT[4] : [0] -2.04 [1] -1.46 [2] -3.21 [3] -2.14 SQUIDBias (uA) = FLOAT[4] : [0] -76 [1] -68 [2] -80 [3] -76 QETBias (uA) = FLOAT[4] : [0] 114.2 [1] 127.2 [2] 117.8 [3] 100.8
[/Equipment/Tower01/Settings/DCRC2/Phonon] VGAGain (multiplicative factor) = FLOAT[4] : [0] 2 [1] 2 [2] 2 [3] 2 LockpointAdjust (mV) = FLOAT[4] : [0] 6.43 [1] 3.02 [2] 3.5 [3] 3.02 SQUIDBias (uA) = FLOAT[4] : [0] 71 [1] 66 [2] 84 [3] 84 QETBias (uA) = FLOAT[4] : [0] -112.6 [1] -107.9 [2] -138.8 [3] -97.7
[/Equipment/Tower01/Settings/DCRC3/Phonon] VGAGain (multiplicative factor) = FLOAT[4] : [0] 5 [1] 5 [2] 5 [3] 5 LockpointAdjust (mV) = FLOAT[4] : [0] -4.67 [1] -2.82 [2] -1.95 [3] -2.53 SQUIDBias (uA) = FLOAT[4] : [0] -84 [1] -86 [2] -72 [3] -88 QETBias (uA) = FLOAT[4] : [0] 120.5 [1] 100.7 [2] 92.5 [3] 119.2
| 1550 | Apply these settings and see pulses on all channels! Triggering shows that pulses are also synchronized. |
|---|---|
| 1553 | Tower = 46.8 mK and slowly falling. |
| 1610 | We haven't flashed or baked yet, but let's just take a quick test data series. |
| 1614 | Start 6 min Bkg series at +4/-4 V with above QET settings, Driver Gain=1, with 1000 initial randoms. Trigger on DIB1pA with threshold of 100ADC bins |
| 1626 | After this, lazylogger was giving errors about full disk when trying to copy data over. This has happened before and it's actually a python version issue. Nick started the odb while in a python3 environment. To fix this, log out of user cdmssoft, change python versions, log back in as cdmssoft, and restart the DAQ. Then lazylogger resumes copying the files properly. Actually, this may be the cause of the Zap errors before too. |
| 1634 | Use DCRC_UI Flash GUI to start 2 hour bake. |
| 1641 | Tower heats to ~115 mK |
| 1740 | Fill LN2 cold trap full. |
| 1920 | Dang, forgot to set detector bias to 0 before baking. Set DCRC1/2 Charge bias = 0/0 V. Use DCRC_UI Flash GUI to start 2 hour bake. |
| 2220 | Tower = 59.6 mK |
| 2225 | Set up triggering on inner and outer phonon channels on both sides of detector. S1pA/S1pF = DCRC2pD/DCRC1pB = 8/8 ADC and S2pA/S2pF = DCRC2pB/DCRC3pB = 8/8 ADC Also adjust all trigger window widths to be: PhononTriggerBaselineLength = 120, ChargeTriggerBaselineLength = 16, PhononTriggerSampleLength = 28, ChargeTriggerSampleLength 5. These are the old default for charge and close to the best available for phonons. |
| 2248 | Start Bkg Bias scan at S1/S2 = 0,+/-4,+/-8,+/-12 V with above phonon settings, Driver gain = 1, with 1000 initial randoms, 30 min data, 30s flash with 30 min cooldown trigger on DCRC1pB/DCRC2pB/DCRC2pD/DCRC3pB = 8/8/8/8 ADC using sequence qbias_scan_r71_pm_0_4_8_12.msl |
| note that after the bake, Tower settled to around 59 mK, which is high - are the DCRCs in a bad state? |