2016/08/10 (Wednesday)
| Setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55(1)/33(2)/50(3), Tower has been cooled below Al transition with mu-metal shield 180 cm below standard position | |
| DCRCs powered overnight, took bg data last night. Pumping on IVC with turbo pump overnight. | |
| 0800 | Tower/MC/Coldplate = 39.8/38.2/160 mK, Still = 1.35 K / 55 μbar, G1/G2 = 200/185 mbar, 1K Pot = 1.53 K / 4.5 mbar, MB = 77.2%. Boiloff rate: good. |
| 1K Pot has been somewhat oscillatory, 1.46-1.55 K, 3.0-5.5 mbar. Leave it for now, maybe this is an OK state. | |
| 0810 | Fill LN2 cold trap bath. |
| 0840 | Yesterday's data looks ok using BatViewer to view pulses, but processing failed at the noise processing stage for some reason. Checked the ODB files to compare the successful data from two days ago to the unsuccessful data today. The only possibly relevant difference found was that Equipment/Tower01/Settings/DCRC4/Trigger/PhononTriggerEnable was set to “y” for one channel from the HPGe test yesterday. I wouldn't think this would matter though because DCRC4 was not enabled and at any rate this would probably affect triggering, not the data. |
| 0849 | Start test run at zero bias with all DCRC4 Phonon Triggers disabled, to see whether autoprocessing can handle it. |
| 0935 | Having difficulty processing any new data. The noise processing is not producing a “pulsedump” folder, and the PSDs fail. One difference between the newer and older data is that the noise in Side2 qInner has increased. Try turning off the DIB2 FETs by entering “wr 30 0” in the Telnet session. This reduces the amplitude of the noise. |
| 0939 | Start test run at zero bias with DIB2 FETs turned off. This test was successful it seems: the autoprocessing produced PSDs. |
| 1003 | Start one 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. DIB2 FETs have been turned off. |
| 1035 | The data above also failed to process, despite the successful test before. Looking at pulses it appears that the FETs have been turned back on. And checking the DIB2 telnet session confirms this. Probably flash-and-take turns the FETs back on as part of the flash sequence. |
| 1044 | Stop run early using Stop Immediately. Set biases back to zero. |
| 1050 | Attempted to change “Vlock” (aka Amp Offset (V)) on the DIB2 qInner charge channel, in the hopes of railing it. Changing this value from 0 to 2 or -2 does shift the wave form down or up, but it doesn't rail it. Values beyond 2 or -2 don't seem to take - these are probably the limits. |
| 1055 | P1 oscillating with 1K Pot between 50 and 60ubar. Turn on Still Heater to 1mW to attempt to increase Still Pressure back to target of 120ubar. |
| 1104 | Attempt a data run manually w/o using the Flash & Take script. Flash detector for 30s manually. |
| 1134 | Turn off DIB2 FETs. Apply -4/+4 Qbias. Manually start one 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 before series. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1204 | Stop run. After randoms finish. Turn Qbias to 0V, and flash for 30s using the Flash & Flash script. Will check to see if FETs are turned on by the script. Indeed they are. When the flashing begins, register 30 is set to 0803, and when the flashing ends, it's set to 0800. So the FET ON bit (the 8 in 0800) is automatically set on register 30 by MIDAS. |
| 1209 | Flashing finished. Wait 25 minutes for cooldown. |
| 1237 | While checking phonon channels before running, tower temp spiked up to 115mK. Perhaps because I powered on DIB2's FET Heater. I wasn't seeing pulses on DIB2 and I thought it might be because the FET was off, so I powered on the FET & its heater to see if that brought the pulses back. That's when I noticed the temperature spike. Now waiting for the fridge to cool down before taking data. FETs currently on, but FET heater off. |
| 1250 | The temperature has reached 40mK, so let's look at pulses. All channels showing pulses. Turn off DIB2's FET. Temperature spike again! Let it cool again. |
| 1256 | Alright, finally with DIB2's FETs off and the tower at 39mK, we're good to go. |
| 1257 | With DIB2 FETs turned off, Manually start one 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1328 | Stop run. After randoms finish, turn Qbias to 0V, and flash for 30s using Flash & Flash script. |
| 1330 | Flashing finished, wait 25 minutes for cooldown. |
| 1356 | Turn off DIB2 FET. Temperature spikes. Wait for it to cool back to 40mK. |
| 1402 | With DIB2 FETs turned off, Manually start one 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1432 | Stop run. After randoms finish, turn Qbias to 0V. Begin warm up procedure by closing V6. |
| 1440 | V6 closed all the way. Turn off Still Heater, close V13B, and Turn off He3 pump. Turn on MC Heater to 1mW. Tower temp = 250mK. |
| 1445 | Close turbo pump valve (with Tower = 350 mK) so that we can monitor IVC pressure. |
| 1457 | Tower temp in mid 800s mK and rising quickly. IVC pressure holding steady at 7.4E-6 mbar. |
| 1513 | Tower temp reaches 1.27K and spikes to approximately 3.05K. IVC pressure = 1.6E-4 mbar (compared to 6.3E-4mbar yesterday). Open up turbopump to begin pumping on IVC. Turn off MC Heater, turn on He3 pump, and open V13b. |
| 1540 | Tower temp at 2.2K and cooling very slowly. Open V6 to 12% in preparation for starting circulation. |
| 1552 | P2 has fallen to 2.8mbar. Tweak open 1K Pot to ease strain from condensation process. |
| 1645 | Fill LN2 cold trap full. |
| 1737 | Tower temp finally below 1K, and pressures stable with V6 open to 15%. Open V6 all the way. |
| Tower has been cooled below Al transition with mu-metal shield at standard position | |
| 1740 | I've created a custom sequence that will wait for 2 hours, then begin taking 8 loops of data. |
| 1745 | Tower temp = 395mK and dropping. Set Qbias to -4/+4 then start my sequence, which will wait 2 hours then start 8 30min background series at -4/+4 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |