2022/03/24 (Thursday)
- Lab in-personnel: Anthony, Kitty, Megan, Matt
| Status | Run 76 in progress |
|---|---|
| Setup | Cable 2/1/3 → diverter/nothing/nothing → DCRC 1/3/4 |
| 1355 | MC/Goldman/Coldplate = 28.9/79.5/140 mK, Still = 1.16 K / 0.130 mbar / 0 mW, G1/G2= 170/168 mbar, 1K Pot = 18° / 1.65 K / 30±2 mbar. MB = 63.4%. |
| 1355 | Goldman = 77.8 mK @ 632 uV excitation |
| 1445 | Worked on phonon channels. As of this morning the situation was that DCRC3 pA/B and all of DCRC4 were showing good pulses, other channels had no pulses. By adjusting QET biases upwards on DCRC3 pC and pD, got good pulses on those (both at 300 uA). These are both Side1 channels which have higher Tc's. The high biases required suggest the detector is pretty cold. Good to see DCRC3pD working because this is Side1pF which didn't work in Run75 and which I rewirebonded - apparently the fix worked. DCRC1 channels are still not showing pulses. Scanning through a full range of QET biases I haven't found transition regions - they look like either they are stuck in s/c or stuck in normal. Should do properly calculated IbIs to assess which state they're in. Retuned DCRC1pB SQUID. |
| 1500 | Try some IbIs on DCRC1 channels. On pA the IbIs is generally linear though there was a SQUID jump at some point. The inferred TES resistance was 430 mOhm which makes no sense - that's too high for the normal resistance. On pB I was seeing the flat-line behavior at high QET-bias that we get with the one channel… this is further confirmation that this is a DCRC issue and not a SQUID issue since we swapped SQUETs this run. On pC we also saw linear IbIs with apparent R=200 mOhm, also too high to make sense. |
| 1630 | Swap out DCRC1 with DCRC6. Configure DCRC6 with the settings from DCRC1. Power it up - extreme heating, MC → 0.6 K (circulation pressures rise too). Turn on the DAQ programs; temperature falls. Temperature rises again when 15V power is off, falls when it is on. |
| 1645 | Three channels on DCRC6 show traces but pC is railed and can't be unrailed. All DCRC3 and DCRC4 channels are railed! Lame. |
| 1655 | Swap back to DCRC1, same config as this morning. Zap SQUIDs on all three DCRCs. |
| MC temperature settled to a lower temperature than this morning - maybe that indicates that DCRC1 was in a “bad state” before and now it's OK… | |
| 1735 | Fill LN2 cold trap bath |