2017/06/11 (Sunday)
| 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) | |
| 0040 | Lab = 22.9 C, 41% humidity |
| 0047 | previous data is all good except for small driver offset adjustment (see yesterday's diary) Tower = 33 mK, bath 82% |
| 0048 | turn down HV, let settle |
| 0055 | short HV and begin 900s bake |
| 0100 | Lab = 23.0 C, 40% humidity |
| 0111 | sequence finished, wait for a little (< 100 mK) then do pre-bias |
| 0116 | start at HV = 100.1 V |
| 0124 | got to HV = 110, Vtest=111.05 → Vdetector = 65.54 V, stay here for 5 minutes |
| 0130 | start with HV = 91 V to try to get to Vdetector of 50 V |
| 0130 | Lab = 23.2 C, 39% humidity |
| 0147 | HV = 80.1 V, Vtest=75.12 mV → Vdetector = 50.01 V |
| 0151 | 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 |
| 0152 | slight adjustment HV = 80 V, Vtest=74.88 → Vdetector = 50.02 V |
| 0300 | Lab = 23.2 C, 39% humidity |
| 0400 | Lab = 23.1 C, 39% humidity |
| 0500 | Lab = 23.1 C, 39% humidity |
| 0600 | Lab = 23.1 C, 39% humidity |
| 0700 | Lab = 23.0 C, 37% humidity |
| 0700 | Lab = 23.0 C, 38% humidity |
| 0800 | Lab = 23.0 C, 38% humidity |
| 0900 | Lab = 23.0 C, 40% humidity |
| 1000 | Lab = 23.3 C, 42% humidity |
| 1100 | Lab = 23.2 C, 42% humidity |
| 1146 | Dial HV down to 0 V and short leads |
| 1149 | Begin 900s bake with DCRCs 1&2 MB = 64.9% Lab = 23.3 C, humidity = 42% |
| 1151 | Fill LN2 cold trap full. |
| 1215 | Pre-bias to HV = 110.0 V, wait to settle. Tower = 53.2 mK and cooling, all channels ok. |
| 1225 | Dial up HV = 129.3, Vtest = 173.2 mV → Vdetector = 59.77 V |
| 1227 | Dial HV down to 110.0 V, targeting Vdetector = 50.0 V, wait to settle. |
| 1231 | HV = 104.8, Vtest = 143.5 mV → Vdetector = 50.81 V |
| 1237 | HV = 104.8, Vtest = 135.6 mV → Vdetector = 50.37 V. Tower = 35.02 mK |
| 1239 | 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. |
| 1240 | HV = 104.8, Vtest = 135.01 mV → Vdetector = 50.61 V |
| 1250 | Data was looking weird on Batviewer… I stopped the run and will check all channels. They all look fine. Restart data. |
| 1252 | 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. |
| 1257 | Everything looks normal now. |
| 1300 | Lab = 22.6 C, 43% humidity |
| 1400 | Lab = 22.4 C, 43% humidity |
| 1500 | Lab = 22.4 C, 43% humidity |
| 1600 | Lab = 22.3 C, 43% humidity |
| 1700 | Lab = 22.2 C, 44% humidity |
| 1744 | HV = 104.8 , Vtest = 165.27 mV → Vdetector = 38.6 V (very humid, 44% by meter) |
| 1745 | Tower/MC/Coldplate = 33.1/xx/195 mK, Still = 1.32 K / 0.110 mbar, G1/G2 = 226.4/220.1 mbar, 1K Pot = 1.67 K / 20.0 mbar. Main bath = 57.8%. Predicted level: % |
| 1800 | turn down HV and let settle |
| 1807 | ground detector and do 900s bake Lab = 22.9 C, humidity = 44% |
| 1857 | tried to pre-bias, but it's impossible the highest the power supply goes is HV=129.3 volts and the leakage current meter saturates at 188.88 mV, in this case we only have 54V on the detector |
| 1900 | Lab = 22.5 C, 43% humidity |
| 1920 | OK, I got so frustrated with the high leakage I tried something we discussed at a previous lab meeting (sorry). I stole a bag from the recycle bin (sorry) and cut it in half and sort of wrapped it around the e-box. I stuck a dry nitrogen hose in it (the cylinder has 500 psi in it and I turned the regulator to 5psi flow). After that the leakage voltage started going down very quickly (it had been over 200 mV). I'm going to try to turn the voltage to 50V now and see if it has better leakage properties |
| 1939 | HV = 52.2 V, Vtest = 5.26mV → Vdetector = 50.12 V |
| 1941 | 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. |
| 1941 | my “poor man's purge” seems to be working, at least the leakage is low, It seems like (according to the humidity meter) we also came down by 2% in humidity during that time 44% → 42% so maybe it was partially that too. We will likely be out of dry nitrogen (250 psi in bottle) before the next run, so we can see how the leakage increases |
| 2000 | Lab = 23.1 C, 42% humidity |
| 2100 | Lab = 23.2 C, 41% humidity |
| 2128 | The dry nitrogen ran out and the leakage is up so that Vtest = 31.97 mV → Vdetector = 39.4V, try to adjust voltage |
| 2130 | try HV = 60 V , let settle |
| 2203 | HV = 74.6, Vtest=62.18 → Vdetector = 49.7 V |
| 2205 | Lab = 23.4 C, 41% humidity |
| 2300 | Lab = 23.4 C, 41% humidity |
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