2015/08/28 (Friday)
| Current setup: DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50 | |
| 0905 | Tower/MC(H35)/MC sensor/Cold Plate = 30.9/25.6/41.5/156 mK, Still = 1.31 K / 0.085 mbar, G1/G2 = 150 mbar, 1K Pot = 1.74 K / 22 mbar, Main bath = 30.2%. |
| note | Thermometers on Fridge Out 1 cable (MC Sensor, Still, Cold Plate) are still anomalously high. |
| 0910 | Partially fill LN2 cold trap Dewar – LN2 storage Dewar ran empty |
| 1025 | Studying Front-end gains - what is the maximum setting for this before added noise is seen? With all driver gains at setting=1, look at white noise in baseline. Record the front-end gain setting at which this increases to > 20 mVpp (typical 5 mVpp with front-end gain at zero). |
| Maximum Front-End Gain Settings | |||||
|---|---|---|---|---|---|
| DIB 1 (DCRC55) | DIB 2 (DCRC33) | DIB 3 (DCRC50) | |||
| pA | 26 | pA | 6 | pA | 32 |
| pB | 35 | pB | 6 | pB | 14 |
| pC | 19 | pC | 6 | pC | 30 |
| pD | 19 | pD | 5 | pD | 16 |
Above the maxima shown above typically the strongest noise would appear at the peak pulse at >150 mVpp.
With DIB2→DCRC33, noise (thickness of baseline) begins to slightly increase at front-end gain = 6. Generally front-end gain = 6/7/8 led to noise 4/6/100 mVpp.
| 1530 | Return all front-end gains to 1. Set all driver gains to setting=3 (so total gain is 15 on DCRC33/RevC, 16 on DCRC50/55/RevC.1). Adjust driver offsets to set baselines near -0.7V : |
|---|
| Driver Offsets (V) (with driver gain setting=3) | |||||
|---|---|---|---|---|---|
| DIB 1 (DCRC55) | DIB 2 (DCRC33) | DIB 3 (DCRC50) | |||
| pA | 0.034 | pA | 0.020 | pA | -0.022 |
| pB | 0.028 | pB | -0.010 | pB | 0.026 |
| pC | 0.022 | pC | -0.034 | pC | 0.012 |
| pD | 0.034 | pD | 0.014 | pD | 0.048 |
| 1537 | Take data, -4/+4 V, 15 minutes of noise data (all randoms). Run got bogged down at around 800 events… bad series |
|---|---|
| Thresholds were probably too low, set them back up to reasonable values - this seems to work, no bog-down. | |
| 1545 | Take data, -4/+4 V, 1000 randoms. This is noise with higher driver gain to compare to previous noise. Standard QET biases. |
| 1547 | Take data, -4/+4 V, ~7000 randoms (probably not necessary) |
| 1609 | Zero Q bias, flash 30 seconds |
| 1425 | Commence LHe transfer (20.9%) |
| 1500 | Cease LHe transfer (92.7%). |
| 1630 | Place Cf source in shield at detector level for weekend activation |
| 1632 | Fill LN2 cold trap full. |