2016/11/15 (Tuesday)
| Setup: DIB1/3/4 → 3.2 MHz filters → cables1/2/3 → DCRC55(1)/33(2)/50(3) | |
| Overnight: taking data with coincidence trigger from NaI detector, 88Y source in lead castle behind fridge | |
| 0915 | Tower/MC/Coldplate = 33.1/35.8/220 mK, Still = 1.2 K / 110 μbar, G1/G2 = 181/173 mbar, 1K Pot = 1.69 K / 26 mbar. MB = 65.3%. Boiloff rate: a little faster than slow-mode |
| 0920 | Fill LN2 Coldtrap. |
| 0930 | Return 88Y source to safe. |
| 1355 | Finish mini-IbIs on DCRC1 channels |
| 1540 | Finish mini-IbIs on DCRC2 channels |
| 1615 | Finish mini-IbIs on DCRC3 channels |
| 1630 | Put all channels back to their previous QET biases and readjust offsets so that all baselines are near -0.8 V |
| IbIs results | ||||||
| Channel | QET bias [μA] | Rpar [mΩ] | Rn [mΩ] | Rop [mΩ] | Rop/Rn | Rop/(Rsh+Rp) |
|---|---|---|---|---|---|---|
| DCRC1pA | 182 | 8.97 | 96.1 | 53.8 | 56% | 1.63 |
| DCRC1pB | 185 | 8.54 | 89.8 | 46.9 | 52.2% | 1.44 |
| DCRC1pC | 185 | 9.84 | 67.6 | 42.4 | 62.7% | 1.25 |
| DCRC1pD | 190 | 11.31 | 94.8 | 45.3 | 47.7% | 1.28 |
| DCRC2pB | -174 | 11.9 | 101.2 | 30.6 | 30.2% | 0.85 |
| DCRC2pC | -173 | 11.39 | 106.9 | 50.6 | 47.3% | 1.43 |
| DCRC3pB | 207 | 14.36 | 106.8 | 61.9 | 58% | 1.61 |
| DCRC3pC | 165 | 14.66 | 100.7 | 40.1 | 39.8% | 1.04 |
| DCRC3pD | 202 | 13.7 | 82 | 38.9 | 47.4% | 1.03 |
It's worth noting how close the operating TES resistances are to the Rshunt+Rparasitic limit (below this, feedback shouldn't work). See the final column. Some are extremely close, and in fact in one case Rop is smaller than Rsh+Rp. This channel shows good pulses and stability like all the others, so very probably these measurements are not accurate.
| 1633 | Main bath = 54.0% |
|---|---|
| 1640 | put 88Y source out in lead castle behind the cryostat |
| 1651 | tuned lower threshold on NaI coincident detector down to 40mV to give ~ 100Hz, this is to get some non-fully collected gammas from the source and increase the efficiency for comptons |
| 1655 | test run in these conditions with 40mV threshold |
| 1707 | test run in these conditions with 92mV threshold, this is more like 100Hz, triggering now has less frequent pileup |
| 1651 | Start sequence of 15 one-hour data series of 0V data with Frontend Gain = 5/2/5, OG = 8/3/8, with 2000 beginning randoms (because of increased pileup from higher source rate), with no flashing in between series, triggered with NaI coincidence setup (low threshold 92mV high threshold 124mV and 1100V on NaI detector) using DCRCX (DCRC4) PhA. |
| 1721 | Fill LN2 cold trap full. |