2016/07/19 (Tuesday)
| Setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55(1)/33(2)/50(3) | |
| DCRCs on overnight. Note: fridge was cooled below Al transition with mu-metal shield at standard position | |
| Yesterday circulation was restarted but some mixture was left in the dump. | |
| 0705 | Tower/MC/Coldplate = 86/87/159 mK, Still = 1.16 K / 0.085 mbar, G1/G2 = 175/155 mbar, 1K Pot = 1.43 K / 1.7 mbar. MB = 72.0% |
| Boiloff note: this rate is better than last time. It is typical of the no-taconis boiloff rate we achieved previously. We released pressure from the bath several times after yesterday's fill, so maybe this is the way to do things now. | |
| 0710 | Open 1K Pot needle valve a few degrees more |
| 0711 | Open V14 to pull mix from dump into circulation. G1/G2 → 400 mbar, close V14 again to let pressures settle. Tower rises to 220 mK then falls again. |
| 0715 | Fill LN2 cold trap bath. |
| 0722 | Tower = 75 mK and falling, Still = 0.150 mbar, G1/G2 = 310/285 mbar and falling, 1K Pot = 1.69 K / 30 mbar. Open V14 again. G1 peaks around 400 mbar, still rises to 200 mbar then falls again. Leave V14 open. |
| 0750 | Still has fallen to 0.7 mbar. Close V14, isolating dump. |
| 0751 | Tower/MC/Coldplate = 38.9/34.0/158 mK, Still = 1.44 K / 0.130 mbar, G1/G2 = 260/230 mbar, 1K Pot = 1.63 K / 14 mbar. |
| 0805 | Relock and adjust driver offsets on phonon channels, all show pulses, noise doesn't look too bad currently. |
| note: reasonably stable behavior from DAQ by setting a large number of initial randoms (no final randoms) before using pulse viewer and using DCRC Control in the browser to adjust QET settings. Not using any of the pulse viewers settings, don't trust them. | |
| 0810 | Zap SQUIDs (from DCRC Control/Tools, set to zap DCRC's 1-3, channels A,B,C,D, on/off = 2/30 s, iterations = 2) |
| 0815 | Check pulses again, relock one of them, all OK. Accidentally left on logger so there will be a couple of spurious series written to disk. |
| 0817 | |
| 0820 | Tower only heats to 100 mK during flash. Is this normal? Check LED settings? |
Differences between LED settings now and at the end of Run 56 (same setup):
| category | setting | then | now |
|---|---|---|---|
| [/Equipment/Tower01/Settings/DCRC1/LED] | LED1Current (mA) | -0.6 | 0.6 |
| [/Equipment/Tower01/Settings/DCRC1/LED] | LED2Current (mA) | -0.6 | 0.6 |
| [/Equipment/Tower01/Settings/DCRC2/LED] | LED1Current (mA) | -0.6 | 0.6 |
| [/Equipment/Tower01/Settings/DCRC2/LED] | LED2Current (mA) | -0.6 | 0.6 |
| [/Equipment/Tower01/Settings/DCRC3/LED] | LED1Current (mA) | -0.6 | 0.6 |
| [/Equipment/Tower01/Settings/DCRC3/LED] | LED2Current (mA) | -0.6 | 0.6 |
so it looks like for G106a all of the LED currents should be negative (at least that's what we did in Run 56) but currently they are all positive.
| 0845 | Stop run before data taking begins. Reset all LED currents to -0.6 mA. |
|---|---|
| 0845 | Tower/MC/Coldplate = 35.4/28.7/156 mK, Still = 1.34 K / 0.120 mbar, G1/G2 = 225/200 mbar, 1K Pot = 1.58 K / 6.5 mbar. |
| 0848 | |
| 0850 | Again tower only heats to 100 mK, changing LED currents to negative doesn't seem to have changed anything |
| 0855 | Abort series again, because MIDAS set the LED currents back to 0.6 mA. This is hardcoded in the flashandflash.py script in /home/hep/cdmssoft/repositories/MidasDAQ/online/scripts/pysequencer as discussed on June 6 during Run 58. On that day David modified the file because the USD1 LEDs required positive currents. I have now modified it back to negative currents. For good measure I am also modifying the currents manually in the ODB. |
| 0910 | Tower = 35.2 mK |
| 0911 | Start a 30min background series at |
| failed to set biases in above series. Must remember that if you stop a series early during cooldown period the bias will have been set to zero by the DAQ. | |
| 0915 | Tower went higher, to 200 mK, still not very high. But the ODB has kept the LED currents at -0.6 mA, so this seems to have worked |
| 1010 | Series ended. Check all phonon channels – All showing pulses. |
| 1013 | Start a 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms, with 30s flash and 25 minute cooldown between series. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1115 | Sequence done. Begin warm up procedure by closing V6. |
| Once V6 is closed, close V13A and turn off He3 pump. Turn on MC heater to 1mW. Tower temp already at 260mK and rising. | |
| 1125 | Lower mu-metal shield to 27.7 cm below the standard position. |
| 1130 | Tower = 0.58 K and rising, G1(condenser) 50 mbar and falling, P1 (still) 50 mbar and rising, G2(pump outlet) 120 mbar and flat. Open V3. G1 falls quickly to 15 mbar, P1 rises. |
| 1150 | Tower = 1.23 K and rising. G1(condenser & still) = 20 mbar, mostly flat, P1 (still) = “1000” mbar |
| 1153 | Tower temp shoots up, G1 as well. Tower goes to 2.8 K then falls to 2 K. T1 rises to 50 mbar. Spike in 1K Pot too, to 1.8 K then back to normal. |
| 1200 | Turn off mixing chamber heater. |
| 1205 | Begin cooldown. Turn on 3He pump. Close V3, open V13a. G1/G2 = 110/95 mbar, stable. |
| 1210 | Open V6 to 13.4% before seeing some increase in G1. Also open 1K Pot needle valve a few degrees, pressure was down to 2.6 mbar. |
| 1210 | Tower/MC(H35)/Coldplate = 1.95/2.17/2.9 K |
| 1215 | G1/G2 = 105/90 mbar and flat. Open V6 to 13.6%, pressures rise. |
| 1220 | G1/G2 = 250/230 mbar and still rising. Tower temperature flat. |
| 1223 | G1/G2 = 270/250, starting to flatten off. Open V6 to 13.7%, pressures rise. |
| 1230 | Tower/MC(H35)/Coldplate = 1.74/1.89/2.32 K, G1/G2 = 355/325 mbar and flat/falling |
| 1235 | G1/G2 = 350/320 mbar and falling. Open V6 to 13.8%, pressures rise. |
| 1240 | Tower/MC(H35)/Coldplate = 1.65/1.83/2.22 K, G1/G2 = 400/365 mbar and flat. Open V6 to 14%, pressures rise. |
| 1250 | Tower/MC(H35)/Coldplate = 1.59/1.69/2.06 K, G1/G2 = 545/500 mbar and flat/falling. P1(still) falls below 1000 mbar. Open V6 to 14.2%, G1/G2 rise. |
| 1255 | Tower/MC(H35)/Coldplate = 1.30/1.37/1.47 K, G1/G2 = 485/445 mbar and falling strongly. P1(still) = 6.5 mbar and falling. Open V6 to 15%, G1/G2 rise a little. |
| 1310 | Tower/MC(H35)/Coldplate = 0.72/0.62/0.56 K, G1/G2 = 350/320 mbar and falling. P1(still) = 1.6 mbar. Open V6 100%, G1/G2 stay about the same. |
| 1320 | Tower/MC(H35)/Coldplate = 255/207/286 mK, G1/G2 = 350/315 mbar and falling slowly. P1(still) = 0.16 mbar. |
| 1340 | Tower/MC(H35)/Coldplate = 45.2/35.7/155 mK, G1/G2 = 250/225 mbar and falling slowly. P1(still) = 0.16 mbar. 1K Pot = 1.57 K /6.5 mbar. |
| 1410 | Check phonon channels. Readjust driver offsets. All looked good except DIB3pA/pC, which had huge white noise - looked like high front-end gain, so played with lowering that from 5 to 1 then back to 5, and some driver offset adjustments / relocks, now look OK. All good. |
| 1415 | Tower/MC/Coldplate = 36.4/28.8/155 mK, Still = 1.33 K / 0.075 mbar, G1/G2 = 210/195 mbar, 1K Pot = 1.55 K / 5.5 mbar. MB = 61.8% |
| Note: | fridge was cooled below Al transition with mu-metal shield lowered 27.7 cm |
| 1421 | Start a 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms, with 30s flash and 25 minute cooldown between series. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| again Tower rises to about 200 mK during flash | |
| 1500 | Tower = 35.5 mK, Still = 0.095 mbar, G1/G2 = 200/185 mbar, 1K Pot = 1.53 K / 4.5 mbar |
| 1513 | The Mu-Metal shield had not been raised to normal position after the cooldown, so this series may have some strange noise. Raise the mu-metal shield so we can take another series with it in place. |
| 1525 | All pulses still alive. Start a 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms, with 30s flash and 25 minute cooldown between series. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| while doing analysis noticed that most of the QET biases are the same as in March 3, Run 56 except: DIB3pA, which looks like it was changed on purpose (from 120.5 to 110 μA), and DIB2pB which is the same value as its neighbor DIB2pA(112.6 μA), in March DIB2pB was 107.9 μA so that's probably the correct setting. But we'll leave it for now, it's working. | |
| 1625 | All pulses still alive. Start a 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms, with 30s flash and 25 minute cooldown between series. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1655 | Fill LN2 cold trap full. |
| 1729 | Cf source placed on fridge for overnight activation. |
| 1K pot needle valve opened an additional 1/16 turn. | |
| 1730 | Start overnight HPGe run 3.5kV bias, standard amp gains, pole zero modified for pulse undershoot. DCRCX, PA trigger=5ADC |