2017/06/09 (Friday)
| Setup: DIB1/3/4 → 3.2 MHz filters 3/1/2 → cable 3/1/2 →gender changer 3/1/2 → HVConn 1/3/2 → HV 1/2 → DCRC55(1)/DCRC33(2) | |
| PuBe source in paraffin barrel behind shield (west side) | |
| 0042 | came in and saw Vtest is at 13.76 mV, making Vdetector = 50.03V |
| 0043 | the channels still look OK and unrailed |
| 0043 | Tower temp is 33.09 mK, bath level is 80.2% |
| 0046 | Turn down HV |
| 0053 | ground detector and begin 900s bake |
| 0120 | bring up voltage for pre-bias, start at HV = 70V, let settle |
| 0140 | ended up with pre-bias HV = 78.0, Vtest=32.7 (slowly falling) → Vdetector = 64.9V |
| 0204 | settled on HV = 59.4 V, Vtest = 23.44 mV → Vdetector = 50.015V |
| 0206 | Start 5 1-hour data series of 1-sided 50V HV coincidence data with Frontend Gain = (15/10/10)/(4/4/4), OG = 4/2, QET biases = 30 column from table from May 24, with 1000 beginning randoms, no flashing, and a 500ADC bin threshold trigger on DCRC4 pA (external trigger). Running OR trigger of NaI detectors with PuBe source on west side of shield. NaI detector C has 311 mV threshold and detector B has 288 mV threshold |
| 0730 | Tower = 33.1 mK, Main bath = 70.3% Lab = 24.5 C, 36% humidity HV = 59.40 V, Vtest = 29.48 mV → 47.6V. Leakage got worse overnight. |
| 0735 | Dial HV down to 0 V and short leads |
| 0735 | Fill LN2 cold trap bath |
| 0740 | Begin 30 minute bake with DCRCs 1&2 |
| 0815 | Check Tc on DCRC1pC/Side1pD as tower cools. Set QET bias to 0 then apply test signal to QET, 12 mVpp 100 Hz, set to trigger on test signal. Pulses appear at 72.8 mK then TES falls into s/c at about 72.4 mK. This Tc is pretty close to that measured in January. There may be a bit of systematic error - as the detector cools after a bake, heat is flowing out from the detector to the tower, so the tower thermometer may underestimate the detector temperature. So maybe it's even lower than the January measurement, using the DC method. |
| 0820 | Dial HV up to 75.1 V. After 10 minutes Vtest is 37.6 mV (falling slowly) → Vdetector = 60.0 V |
| 0830 | Dial HV down to 62.57 V, targeting Vdetector = 50 V |
| 0910 | HV = 60.97 V, Vtest = 26.49 mV → Vdetector = 50.34 V. A bit high, but the leakage keeps drifting. I'll continue to correct the HV. |
| 0910 | Tower = 33.4 mK, close to base |
| 0911 | Start 3 1-hour data series of 1-sided 50V HV coincidence data with Frontend Gain = (15/10/10)/(4/4/4), OG = 4/2, QET biases = 30 column from table from May 24, with 1000 beginning randoms, no flashing, and a 500ADC bin threshold trigger on DCRC4 pA (external trigger). Running OR trigger of NaI detectors with PuBe source on west side of shield. NaI detector C has 311 mV threshold and detector B has 288 mV threshold |
| 0915 | HV = 60.55 V, Vtest = 26.14 mV → Vdetector = 50.06 V |
| 0927 | A base temperature diversion occurred here, rose to 34.4 mK then cooled back down to 33.2 mK after about 5 or 10 minutes |
| 0930 | HV = 60.55 V, Vtest = 25.62 mV → Vdetector = 50.27 V. Leakage is drifting downward, will continue to correct. |
| 1005 | Another tower T diversion, smaller this time, rose from 33.2 to 33.4 mK then cooled again |
| 1010 | HV = 60.22 V, Vtest = 23.47 mV → Vdetector = 50.80 V. Leakage keeps getting smaller, will continue to correct. |
| 1035 | HV = 59.26 V, Vtest = 21.81 mV → Vdetector = 50.50 V. Leakage keeps getting smaller, will continue to correct. |
| 1055 | HV = 59.43 V, Vtest = 20.97 mV → Vdetector = 50.01 V. |
| 1130 | HV = 58.00 V, Vtest = 20.26 mV → Vdetector = 49.87 V. |
| 1141 | Stop data, dial HV down to 0 V and short leads |
| 1200 | Begin 30 minute bake with DCRCs 1&2 |
| 1300 | Removed overpressure check valve from 1K Pot pump exhaust. This was advice from Paul Crowell, who thought it might be adversely affecting our helium recovery efficiency. |
| 1300 | Dial HV up to 73 V. After 10 minutes Vtest is 28.64 mV → Vdetector = 61.5 V for prebias |
| 1310 | Dial HV down to 59.30 V, targeting Vdetector = 50.0 V |
| 1323 | HV=58.5V, Vtest=21.25 mV → Vdetector = 49.99 V |
| 1326 | failed attempt to start the run, triggering was not on on DCRC4 |
| 1334 | Start 5 1-hour data series of 1-sided 50V HV coincidence data with Frontend Gain = (15/10/10)/(4/4/4), OG = 4/2, QET biases = 30 column from table from May 24, with 1000 beginning randoms, no flashing, and a 500ADC bin threshold trigger on DCRC4 pA (external trigger). Running OR trigger of NaI detectors with PuBe source on west side of shield. NaI detector C has 311 mV threshold and detector B has 288 mV threshold |
| 1450 | HV=58.5V, Vtest=18.78 mV → Vdetector = 50.96 V. Will adjust this a bit. |
| 1545 | HV=57.39V, Vtest=19.60 mV → Vdetector = 49.52 V. Adjusting again. |
| 1600 | Lab = 25.2 C, 34% humidity |
| 1605 | Fill LN2 cold trap bath |
| 1630 | HV=57.99V, Vtest=19.47 mV → Vdetector = 50.17 V. |
| 1832 | Vtest drifted to 23.87 → Vdetector = 48.24 V |
| 1835 | turn voltage down, let settle |
| 1847 | ground detector and do a 900s flash |
| 1849 | took out 22Na source for HPGe calibration |
| 1919 | pre-bias to HV = 73 V, let settle |
| 1943 | maxed out at HV = 85 V and Vtest= 55mV → ~ 63V |
| 1943 | Lab = 23.4 C, 40% humidity |
| 1944 | turn HV=65 V |
| 2019 | voltage adjust painfully slow (41% humidity) best I can do is HV=70.8, Vtest = 52.09 → Vdetector = 49.94 V |
| 2021 | Start 5 1-hour data series of 1-sided 50V HV coincidence data with Frontend Gain = (15/10/10)/(4/4/4), OG = 4/2, QET biases = 30 column from table from May 24, with 1000 beginning randoms, no flashing, and a 500ADC bin threshold trigger on DCRC4 pA (external trigger). Running OR trigger of NaI detectors with PuBe source on west side of shield. NaI detector C has 311 mV threshold and detector B has 288 mV threshold |
| 2026 | Note: I am still doing 22Na calibration on the HPGe, it should not affect the run much because the source can't trigger the experiment and the cryogenic detector is shielded by a shield wall's thickness of lead (5 layers?) |
| 2040 | HV=71.9V, Vtest=57.17 mV → Vdetector = 49.009 V. Adjust again. |
| 2044 | HV=73V, Vtest=58.58 mV → Vdetector = 49.545 V. Frustrating. |
| 2059 | Vtest drifted to 60.2 mV and steadily increasing, can't keep up with voltage corrections |
