2018/09/21 (Friday)
| Setup: DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2 → gender changer 3/?/2 → HVConn 1/3/2 → HV 1/2 → DCRC55(1)/DCRC50(3) 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V) / Ortec 575A(gain=10, shaping = 3us) → x10/x10 attenuator → DCRCX(4) DCRC33(2) → kepco 1kV power supply → HV input |
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| status: | Power failure last night, restarted recovery around ~2000. Things look stable overnight, tower = 29.5 mK |
| 0805 | Zap SQUIDs. Didn't work, DCRC driver crashed. |
| 0911 | Tower/MC/Coldplate = 29.5/30.1/184 mK, Still = 0.0 mW / 1.4±0.1 K / 0.095 mbar, G1/G2 = 132/131 mbar, 1K Pot = 1.60 K / 17 mbar, Turbo on IVC = 0.86 nbar, MB = 70.4% |
| 0915 | Can't telnet to DCRC1, power cycle it. Now we cant telnet to all 4 of them. |
| 0917 | Fill LN2 cold trap. |
| 0920 | Start dcrc_driver01 and zap SQUIDs. Seems to have worked this time. |
| 0930 | All channels operating properly. |
| 0938 | Start 2 hr, -240 V bkg dataset with 4% prebias (-250V) for 5 min, split into 10 min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. Using sequence HVscan-240×1-4_5PreBias-DCRC2_250–30Flash-30wait-2hrData-10minSubRun.msl CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/280/295) uA, Front-End Gains = (10/10/10)/(10/15/10) NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Neg) / Ortec 575A(gain=10, shaping = 3us, Neg) → x10/x10 attenuator → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/10/9 |
| 1120 | DCRC3pC has been railed low the whole time, fix it. |
| 1225 | Remove 22Na source from safe and place inside lead/poly shield at bottom of NW corner. |
| 1232 | Start 1 hr, -240 V 22Na dataset with 4% prebias (-250V) for 5 min, split into 10 min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. Using sequence HVscan-240×1-4_5PreBias-DCRC2_250–30Flash-30wait-2hrData-10minSubRun.msl CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/280/295) uA, Front-End Gains = (10/10/10)/(10/15/10) NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Neg) / Ortec 575A(gain=10, shaping = 3us, Neg) → x10/x10 attenuator → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/10/9 |
| 1348 | Return 22Na source to safe. |
| 1350 | A quick analysis seems to show the noise resolution is a little worse at this bias than at -80V. It could be that what leakage is present has pushed the TESs away from the optimal bias point. Let's play with QET biases a little at -240V. Chose the following by hand, going a little bit above the SC region. QET biases = (270/258/285)/(135/278/292) |
| 1400 | Still biased at -240V, let's take some data like this. |
| 1407 | Start 1 hr, -240 V bkg dataset, split into 10 min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. Using sequence timed_subrun.msl CDMS detector: Driver Gains = 2x, QET biases = (270/258/285)/(135/278/292) uA, Front-End Gains = (10/10/10)/(10/15/10) NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Neg) / Ortec 575A(gain=10, shaping = 3us, Neg) → x10/x10 attenuator → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/D threshold = 8/10 Using a similar method to this, it seems like the noise is worse, σ = 30.4 eVee, in this configuration. |
| 1421 | DCRC3pC is railed, recover it. |
| 1513 | Turn down HV using change_HV_240_to_0_DCRC2_250V.msl |
| 1530 | Bring PuBe source into lab and place at south wall of lab. |
| 1534 | Flash detector. |
| 1535 | Start 1hr NaI calibration dataset with NaI detector: 1.1kV → NaI B/C → → Ortec 452(gain=5, shaping = 6 us, output=10V, Neg) / Ortec 575A(gain=10, shaping = 3us, Neg) → x10/x10 attenuator → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC4pA/B threshold = 5/5 This dataset still didn't show the 4.4MeV gamma line as expected. Not sure what's going on here… |
| 1705 | Move PuBe source to standard position behind lead heap on west side of fridge. |
| 1707 | Fill LN2 cold trap full. |
| 1721 | Restore standard QET biases = QET biases = (280/260/305)/(140/280/295) uA Note: It was later discovered that they were actually set to : (280/280/305)/(140/280/295) uA |
| 1735 | Doesn't look like the NaI signal will be much different and the -240V data has a little worse noise that -80V. So we don't have a clear way to improve on what's been done already. Maybe there is an optimal bias between -80V and -240V? Let's do a bias scan overnight to check it out. If there's a clear improvement, then we can use it for PuBe search data over the weekend. |
| 0938 | Start PuBe bias scan sequence of 1 hr datasets at HV = 0,-50,-75,-100,-125,-150,-175,-200,-225 V with 10% prebias for 5 min, split into 10 min subruns, with CDMS and NaI detectors running and DCRC2 as HV controller. Using sequence HVscan-0_50_75_100_125_150_175_200_225-10_5PreBias-DCRC2_250V-30Flash-30wait-1hrData-10minSubRun.msl CDMS detector: Driver Gains = 2x, QET biases = (280/260/305)/(140/280/295) uA, Front-End Gains = (10/10/10)/(10/15/10) NaI detector: 1.1kV → NaI B/C → Ortec 452(gain=5, shaping = 6 us, output=10V, Neg) / Ortec 575A(gain=10, shaping = 3us, Neg) → x10/x10 attenuator → DCRC4PB/PA, Driver Gains = 1/1, PhononWaveFormLength = 1024 (512 samples), PhononPrepulseSamples = 64 (64 samples) 1000 BOR randoms, trigger on DCRC3pB/C/D threshold = 7/10/9 |