2021/07/20 (Tuesday)
- Lab in-personnel: Pramod and Giulia
| Status | Run 74 in progress. First cooldown aftr IVC rebuild. |
|---|---|
| Tower thermometer is reading high, probably this is a thermometer problem and the actual temperature is much lower. High noise in some of the charge channels. | |
| Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/Source_mover_board+HV_diverter_board → DCRC50(3)/55(1). Kepco 40V supplye → HV BNC. No lead/poly shield. Currently both DCRCs are on. | |
| 1101 | Tower/MC/Coldplate = 160/35.6/194 mK, Still = 1.41 K / 0.075 mbar / 0 mW, G1/G2= 295/266.2 mbar, 1K Pot = 1.62 K / 20±1 mbar. MB = 66%. |
| 1120 | Fill LN2 cold trap bath. |
| 1253 | At 10kHz noise in DCRC3qI/qO/DCRC1qI/qO = 32/2.95/2.72/107 e-6. This is q3/q1/q4/q2 At 3kHz (peak) noise in DCRC3qI/qO/DCRC1qI/qO = 6191/91/39/6237 e-6 |
| These are higher but some close to yesterday. | |
| 1305 | Place Na-22 source 30 cm East of detector (center-to-center distance) on stand in lead castle. |
| 1305 | Increase ChargeWaveFormLength in DCRC1&3 from 8192→65536. This will increase the trace length from 1.6384 ms to 13.1072 ms. |
| 1310 | Apply -15V bias to Side 2. Now we are seeing some pulses. |
| 1320 | Event rate in DCRC1qI(q4) for pulses above 0.1V: 152 pulses counted in 200 traces. 58.0 Hz. |
| 1325 | Event rate in DCRC3qO(q1) for pulses above 0.1V: 107 pulses counted in 200 traces. 40.8 Hz. |
| 1325 | Dial bias down to 0V and flash detector for 60 seconds |
| 1325 | Restore ChargeWaveFormLength to standard settings. |
| 1411 | Start 50 min series of 0V/-15V (bias applied after 100 sec), with Na-22 source at 0.30 m, with 1000 beginning randoms, trigger threshold 100/50/40/180 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Start sequence with Start button. |
| 1503 | Dial bias down to 0V and flash detector for 60 seconds. |
| 1555 | Put Na-22 source back in safe |
| We'll try moving the source during a series again. | |
| 1604 | Start 49 min series of 0V/-15V (bias applied after 60 sec), with 1000 beginning randoms, trigger threshold 100/50/40/180 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Start sequence with Start button. |
| 1619 | Do mv -64, with dwell = 40 and power = 6.8 V. (Around 760 mm/hour) This single move will take about 5 sec and will move the source a total distance of -1.06 mm. Tower jumps from 92 mK to 3.43 K, then starts cooling. Traces look crazy for several seconds but then pulses come back - they maybe look smaller? This is of course a very different temperature. |
| 1625 | Tower = 1.0 K and falling |
| 1629 | Tower = 0.6 K and falling |
| 1634 | Tower = 0.4 K and falling |
| 1640 | Tower = 0.3 K and falling |
| 1647 | Tower = 0.25 K and falling |
| 1702 | Dial bias down to 0V and flash detector for 60 seconds |
 |
| huh??? |
20210720_log.xlsx