| | Setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50 |
| | Cf source near detector for overnight activation. |
| 0830 | 1KPot was very low, 1.5 K / 3.5 mbar (has been this way for last 16 hours at least). Tweak needle valve open a few degrees, → 1.72 K / 20 mbar. |
| 0840 | Tower = 35.6 mK, Still = 0.085 mbar, G1/G2 = 115/105 mbar, Main bath = 15.3% |
| 0841 | Start LHe transfer at 12.8% |
| 0903 | Fill LN2 cold trap Dewar |
| 0950 | Cease LHe transfer (64.5%). |
| 1100 | 1KPot fell low again, 1.55 K / 5 mbar. Tweak needle valve wider again. Note that both times the pot pressure shot up initially off-scale, kind of strange, then settled. → 1.73 K / 26 mbar. |
| 1118 | Put Cf source back in safe. |
| 1120 | MIDAS relinquishes control of DCRCs. Open up LabVIEW to check settings and pulses. As always, when reading values in LabVIEW that were set by MIDAS, several values appear slightly off (i.e. Frontend Gain of 5.177 instead of the expected 5.) The SQUID biases for DIB1 pA,B,C are all larger than previous LabVIEW values by ~20uA. This was most likely due to setting the values differently rather than some rounding error between the two programs. |
| | When viewing the pulses, DIB1 pB appears to have a test signal applied, and all the DIB1 phonon channels are showing upside down pulses. Reading register 3d shows 0DD7. Writing 3d 09D7 gets rid of phB's test signal, though all the pulses are still upside down. |
| | DIB2 channels (including charge) are railed. |
| | DIB3 doesn't seem to be communicating properly. All the channels may be railed, but it's unclear at first glance. |
| 1130 | DIB3 still not responding to Detector Readout VI. Playing around in Putty, I executed “wr 15 0 → wr 15 20” to enable writing to the DCRC, which did the trick. I'm now seeing channels on DIB3 (DCRC50). phC is railed, and the other channels are showing test signals. Reading register 3d gives 0DD7, so wr 3d 09D7, and the test signals disappear. DIB3 is just showing noise though, not pulses. |
| 1135 | Apply all the DCRC settings from the LabVIEW XML files for last run. (The values from 2015-09-17). DIB3's channels all rail, so adjust the Driver Offsets till their baselines are ~-0.7V. |
| 1144 | While applying settings to DIB3, all phonon channels showing pulses except for phA, which would not come out of rail. All of a sudden, all phonon channels disappear and displays on Detector Readout stop triggering. Cannot get displays to update, and Detector Readout will not stop when STOP button is pushed. Abort Detector Readout and restart. |
| | DIB3 phB, C, and D are still showing pulses as they were. phA is still railed. It must have been an issue w/ the program, and not the DCRC. Back to setting the values. phA still won't unrail except at extremely high Driver Offsets (~1.2V), but even then it's just showing jagged noise. I'll come back to that one. |
| 1153 | DIB2's channels (including charge) are all railed. Turn on FET heaters in hopes of awakening the charge channels. It's not working… Writing 15 0, wr 15 20 allowed the channels to start updating. In addition, register 3d read 0DD7, so wr 3d 09D7 and no more test signal. phA is showing noisy upside down pulses, phB shows good pulses, while phC and phD are railed. Apply old settings. |
| | DIB2 phB,C,D looking good with old settings. phA still showing noisy upside down pulses. SQUID bias and QET bias are correct signs, so that's not the issue. Flipping the QET bias does cause the pulses to flip upright, but the pulses are still ugly. I'll come back to that one too… |
| 1210 | After loading up the old settings, DIB1 looks good. |
| 1223 | Back to DIB2. phA still showing upside down pulses. Let's look at the modulation curve. Looks like it may need a zap, so ZAP phA SQUID twice. |
| | phA still showing upside down pulses. |
| 1300 | After looking at the modulation curve (it's an ugly ugly curve, presumably the SQUID's damaged somehow), lower the SQUID bias to 71uA, and increase the lock point to 6.43mV. After applying the rest of the settings, phA shows upright pulses, albeit still somewhat noisy. |
| 1307 | Back to DIB3 phA. Still railed unless the ridiculously high Driver Offset's applied. Try looking at the modulation curve, but I can't get the test signal to show up. Read register 45, gives back 3188 instead of the expected 3139. The first of the 8s indicates that phA Zap is still enabled. WR 45 3131 to get things back to normal. |
| | phA now shows an upside down pulse. Time to look at the modulation curve. |
| 1315 | Test signal still not showing up. WR 15 0, WR 15 20 to Putty session again. Now the test signal shows up. Weird. After seeing modulation curve, lower SQUID bias from -84uA to -70.3uA. Change LockPoint from -4.66mV to -3.89mV. |
| 1322 | Now phA only shows up as occasional odd pulses, but for the most part just shows noise. By increasing QET bias from 100.5uA to 120.5uA, I was able to get regular looking pulses to show up. I guess the change in base temperature may have affected the necessary QET bias (though I would have thought it should necessitate a lower QET bias rather than a higher one…). Regardless, all the channels are operational now. |
| 1327 | Now that phA is working, change the SQUID bias and Lockpoint back to the original values of -84uA and -4.66mV, respectively. Still showing good pulses. |
| 1702 | Place Cf source near detector for overnight. |