2021/02/26 (Friday)
- Lab in-person: Derek
- Virtual partner: Matt
| Status | Run 74 in progress. |
|---|---|
| Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/motor_board+HV_board → DCRC50(3)/55(1). No lead/poly shield. | |
| 1205 | Tower = 96.3 mK |
| Yesterday we tried 7V data with trigger thresholds of 100 for each channel, but it was overtriggering, so we increased to 200/300. But those higher thresholds seem to be above 60 keV. Let's try again at 150. | |
| 1208 | Start 31min series of 7V data (bias applied after 1 min), with 1000 beginning randoms, trigger threshold 150/150/150/150 on DCRC3qI/qO/DCRC1qI/qO, no in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use sequence r74_takeandflash_dcrcbias.msl |
| 1215 | DCRCs are not overtriggering. Seems like we can go still lower than 150. It's strange, the overtriggering seems like it may be occurring at random times, a sort of glitch - not sure. |
| This data did not write to disk. Why not?? Messages doesn't show the lazy logger stuff it usually has, it just says the run started and stopped - as if Write Data wasn't selected. But the sequencer has Write Data built in. Hrumph… | |
| 1227 | Derek enters lab. |
| 1321 | Start a test series of 0V data just to see if it will write the data. Turn on Write Data on the ODB and press the Start button. (Left this going for 30 minutes accidentally) |
| Seeing LazyLogger messages, so it's writing to disk now. Hmm. I turned off the Pulse Viewer, which I had left on before. Maybe that somehow interfered with it… | |
| 1350 | Tower = 97.3 mK, mostly cooled back to base |
| 1352 | Start 31min series of 7V data (bias applied after 1 min), with 1000 beginning randoms, trigger threshold 150/150/150/150 on DCRC3qI/qO/DCRC1qI/qO, no in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use sequence r74_takeandflash_dcrcbias.msl |
| 1355 | Looks like data is writing |
| I'm not seeing anything that looks like a 60keV peak in q4. Maybe try lowering the thresolds again. | |
| 1518 | Tower/MC/Coldplate = 99/30.9/188 mK, Still = 1.48 K / 0.130 mbar / 0 mW, G1/G2= 180.5/176.8 mbar, 1K Pot = 1.67 K / 36±2 mbar. |
| 1534 | Fill LN2 cold trap bath. |
| 1535 | MB = 60.5% |
| 1605 | The triggering Baseline and Sample widths are currently set to 16/5. Looking at pulses in BatViewer it may be better to have, say, 24/12 to more efficiently cut out high frequency noise. Let's experiment a bit. |
| 1620 | Do some trigger testing: set bias to 5V, set charge trigger Baseline/Sample = 24/12 for both DCRCs. Note that changing these from the initial values during a run caused constant triggering, but changing while the run was stopped seemed to be ok. Tried thresholds of 50 for each channel individually and didn't see overtriggering. Then set biases back to 0. I guess I'll wait a little for it to neutralize a little before trying another series, still may not be totally neutralized. (Had the 5V bias on for 11 minutes.) |
| 1640 | Tower = 98.0 mK |
| 1644 | Start 31min series of 7V data (bias applied after 1 min), with 1000 beginning randoms, trigger threshold 50/50/50/50 on DCRC3qI/qO/DCRC1qI/qO, new trigger Baseline/Sample=24/12, no in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use sequence r74_takeandflash_dcrcbias.msl |
| 1655 | Pulse viewer suggests that it's maybe overtriggering - doesn't look constant but pulses are few and far between, and rarely at the right start time. So - change thresholds on the fly to 80/80/80/80. |
| 1658 | Crap - I had not enable the triggers. So I was only seeing randoms. Enable them now and set randoms to 0 Hz and thresholds back to 50/50/50/50 |
| OK looks like nice pulses now | |
| 1820 | Tower = 100 mK. Seems to have settled but it's not as low as it was. |
| 1822 | Start 31min series of 7V data (bias applied after 1 min), with 1000 beginning randoms, trigger threshold 50/50/50/50 on DCRC3qI/qO/DCRC1qI/qO, no in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use sequence r74_takeandflash_dcrcbias.msl |
| OK, looking at this data it seems clear that the thresholds are well below 60 keV. But I don't see any peaks in any of the channels. What gives?? |