2017/12/06 (Wednesday)
| Setup: DIB1/3/4 → SL 27/19/20 → 3.2 MHz filters → cables 2,1,3 → HV board inputs 1,3,2 → HV board outputs 1,2 → DCRC55(1)/50(3). Also DCRC4 is powered and hooked up to control the HV setting. | |
| 0855 | Tower/MC/Coldplate = 21.6/23.9/149 mK, Still = 1.2 K / 0.100 mbar, G1/G2 = 248/229 mbar, 1K Pot = 1.62 K / 24 mbar, MB = 33.9% new milestone: Tower thermometer resistance is above 300 kΩ! |
| 0900 | Fill LN2 cold trap full. |
| 0915 | Increase Driver Gains to x8 and adjust Driver Offsets to get all baselines around -0.3 V. |
| 0917 | Dial HV up to 70 V with prebiasing using sequence changeHV_0_70_preBias15_5.msl |
| 0925 | HV = 69.89 V, V_leak = 3.14 mV |
| 0945 | Messing with Driver Gains and Driver Offsets and trigger threshold. A lot of channels were ADC saturating, so I've set the Driver Gains down to x2. |
| 0953 | Start 60-minute background data series at HV = 70V, Driver Gains = 2x, QET biases = 480/360/450/480/380/490 uA, Front-End Gains = 10/5 on DCRC1/3, 1000 initial randoms, trigger on DCRC3pD (Side1pF) threshold = 12 |
| 0955 | HV = 69.89 V, V_leak = 2.96 mV |
| 1030 | HV = 69.87 V, V_leak = 2.77 mV |
| 1053 | Stop data series. |
| 1055 | Estimate event rate from random traces. Set PhononWaveformLength on DCRC1 to 131072 which is 52.4288 ms and counted visible pulses in 42 pA traces. Counted 70 pulses in 2.20201 seconds, so event rate is around 31.8 ± 4 Hz. |
| 1108 | Place PuBe source in lab, in its paraffin barrel centered behind lead wall behind cryostat shield. |
| 1110 | Estimate event rate from random traces. Set PhononWaveformLength on DCRC1 to 131072 which is 52.4288 ms and counted visible pulses in 24 pA traces. Counted 92 pulses in 2.25829 seconds, so event rate is around 73.1 ± 8 Hz. |
| 1122 | Start 60-minute PuBe data series at HV = 70V, Driver Gains = 2x, QET biases = 480/360/450/480/380/490 uA, Front-End Gains = 10/5 on DCRC1/3, 1000 initial randoms, trigger on DCRC3pD (Side1pF) threshold = 12 |
| note that detector has been biased for about 2 hours without flashing. Will probably flash after this run. | |
| DCRC3pB railed some time during the 5th dump | |
| 1125 | HV = 69.87 V, V_leak = 2.69 mV |
| 1220 | HV = 69.86 V, V_leak = 2.66 mV |
| 1222 | Stop data series. |
| 1225 | Adjust driver offset on DCRC3pB. It did not fall into superconducting, but it did require an adjustment to the offset. |
| 1230 | Change Front-end Gain on DCRC3pB from 5 to 3. Maybe this will make it more stable, stay locked. |
| 1231 | Start 60-minute PuBe data series at HV = 70V, Driver Gains = 2x, QET biases = 480/360/450480/380/490 uA, Front-End Gains = 10/10/103/5/5, 1000 initial randoms, trigger on DCRC3pD (Side1pF) threshold = 12 |
| DCRC1pC has pretty bad oscillations in the pulses, may need to reevaluate its QET bias | |
| DCRC3pB shifted several times and was practically railed by the end of Dump 16. sucks. | |
| 1330 | HV = 69.86 V, V_leak = 2.66 mV |
| 1332 | Stop data series. Detector was biased without flashing for about 4 hours. |
| 1335 | Adjust driver offset on DCRC3pB. Hoping that it becomes stable. Maybe should look at SQUID settings again. |
| 1335 | Dial HV down to zero using sequence script changeHV_70_0.msl |
| 1405 | Flash LEDs on DCRCs 1 and 3 for 30 seconds |
| note: after 30 minutes Tower was still about 0.4 mK above base. It reached base after about 45 minutes. | |
| 1416 | Begin LHe transfer @ 26.0% |
| 1530 | Tried adjusting DCRC3pB SQUID settings but they appear to be optimal already. Restore Front-end Gain to 5. |
| 1535 | Dial HV up to 70 V with prebiasing using sequence changeHV_0_70_preBias15_5.msl |
| 1538 | Remove PuBe source from lab and put in PAN 443b storage. |
| 1545 | Tower = 21.6 mK |
| 1550 | Estimate event rate from random traces. Set PhononWaveformLength on DCRC1 to 131072 which is 52.4288 ms and counted visible pulses in 42 pA traces. Counted 65 pulses in 2.20201 seconds, so event rate is around 29.5 ± 4 Hz. |
| 1555 | Start 60-minute background data series at HV = 70V, Driver Gains = 2x, QET biases = 480/360/450480/380/490 uA, Front-End Gains = 10/10/105/5/5, 1000 initial randoms, trigger on DCRC3pD (Side1pF) threshold = 12 |
| 1612 | Baseline of DCRC3pB has crept down a bit. Try adjusting Driver Offset from 0.5 to 0.4 |
| 1620 | Triggering on noise a bit too often I think. Raise trigger threshold from 12 to 15. |
| 1628 | Triggering well above noise now. Lower trigger threshold from 15 to 14. |
| 1655 | Stop data series. |
| 1704 | Place PuBe source in lab, in its paraffin barrel centered behind lead wall behind cryostat shield. |
| 1710 | Fill LN2 cold trap bath |
| 1715 | Dial HV down to zero using sequence script changeHV_70_0.msl |
| 1718 | Start 60 minute PuBe data series at HV = 70 V followed by flash using sequence HVseries-70V-15_5Prebias-30Flash-30wait-1hrData.msl Driver Gains = 2x, QET biases = 480/360/450/480/380/490 uA, Front-End Gains = 10/10/10/5/5/5, 1000 initial randoms, trigger on DCRC3pD (Side1pF) threshold = 14. |
| 2041 | DCRC3PB railed low some time in the 37th dump. |
| 2247 | Change DCRCpB,PD driver offsets. Doing it remotely via the DCRC control GUI. Initially, the values displayed in the GUI were wrong, which really messed up the driver gains when I adjusted them from what I thought the current values were. |
| 2256 | Start 60 minute PuBe data series at HV = 70 V followed by flash using sequence HVseries-70V-15_5Prebias-30Flash-30wait-1hrData.msl Driver Gains = 2x, QET biases = 480/360/450/480/380/490 uA, Front-End Gains = 10/10/10/5/5/5, 1000 initial randoms, trigger on DCRC3pD (Side1pF) threshold = 14. |