2019/06/18 (Tuesday)
| Setup | DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2 → gender changer ?/3/2 → HVConn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1) DCRC33(2) → 1kV power supply → HV input Three walls of the lead/poly shield are up. |
|---|---|
| 0925 | Tower/MC/Coldplate = 40.9/30.9/201 mK, Still = 1.29 K / 0.090 mbar, G1/G2 = 150/141 mbar, 1K Pot = 1.63 K / 22 mbar. MB = 34.5% |
| 0930 | Fill LN2 cold trap bath |
| 1010 | Remove low-pass filter from HV line. |
| 1015 | Let's try to understand the 0V noise better. We'll take SC data to get a look at the Passive Johnson Noise (PJN) and we'll also need the IbIs slope in SC and transition to see how much the PJN contributes to noise in transition. Start with IbIs slopes. We'll measure each channel with all the others still in transition. |
| Channel | Ib (uA) | Vo (V) | Notes | Ib/Is slope |
|---|---|---|---|---|
| DCRC1PB | 415 | -0.8778 | 28.8116428442194 | |
| 420 | -0.8759 | |||
| 425 | -0.8696 | |||
| -5 | 0.6597 | -2.35381571640133 | ||
| 0 | 0.6041 | |||
| 5 | 0.5497 | |||
| DCRC1PC | 475 | -0.5671 | 12.35495951417 | |
| 480 | -0.5557 | |||
| 485 | -0.5462 | |||
| -5 | 0.5107 | -2.5134286188191 | ||
| 0 | 0.4604 | Drippy noise | ||
| 5 | 0.4077 | Strong resonance at 100 kHz | ||
| DCRC1PD | 445 | 0.0616 | 3.95275816581158 | |
| 450 | 0.0949 | |||
| 455 | 0.1271 | |||
| -5 | 0.051 | -2.08814335055207 | ||
| 0 | -0.0111 | |||
| 5 | -0.073 | |||
| DCRC4PA | 485 | -0.9169 | 8.81225781721876 | |
| 490 | -0.9009 | |||
| 495 | -0.8876 | |||
| -5 | -0.2884 | -3.65187660253175 | ||
| 0 | -0.3043 | |||
| 5 | -0.3536 | |||
| DCRC4PB | 395 | -1.0005 | 6.45581928792262 | |
| 400 | -0.9787 | |||
| 405 | -0.9605 | |||
| -5 | 0.1943 | -1.95417940344415 | ||
| 0 | 0.1278 | |||
| 5 | 0.0618 | unstable, slowly rises | ||
| DCRC4PC | 485 | -1.035 | strong oscillations | |
| 488 | -1.0198 | 6.2730242719178 | ||
| 490 | -1.0106 | |||
| 495 | -0.9907 | |||
| -5 | 0.3482 | -2.22257019454358 | ||
| 0 | 0.2898 | |||
| 5 | 0.2317 | unstable, slowly rises |
| 1121 | Start a 5 min SC series at HV = 0 V CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0/0/0)/(0/0/0) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR, 5Hz InRun randoms |
|---|---|
| 1128 | Return QET biases to standard values: DCRC4/1 QET biases = (490/400/490)/(420/480/450) uA |
| 1130 | Set SQUID bias and lockpoint of unused channels (DCRC1PA and DCRC4pD) to 0. |
| 1154 | Begin strong neutron activation of detector by hanging PuBe source in small bucket inside NW corner of shield. (targeting 2hr4min) |
| Tower temperature increases 40.9→41.9 mK when source is introduced | |
| 1358 | End strong neutron activation by returning PuBe source to its paraffin-filled transfer tub. Almost exactly 124 minutes of strong activation |
| Tower temperature returns to base after about 5 minutes. | |
| 1400 | Return PuBe source to storage in PAN 443 |
| 1410 | Check channels - all look good (thanks Nick). Maybe should wait till after transfer to take more data. |
| What trigger threshold should we use? At 6/6/6 we only got 25% write efficiency; at 10/10/10 it was 90%. Let's try 10/10/10. | |
| 1502 | Started LHe transfer. MB = 27.0% |
| 1615 | Fill LN2 cold trap bath. |
| 1618 | Start an 87 min series at HV = 180→400V, rate 2.52V/min, with 10% prebias for 2 minutes, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (490/400/490)/(420/480/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR, 5Hz InRun, and 1000 EOR randoms, trigger on DCRC1pB/C/D threshold = 10/10/10. Use sequence HVdrift_180V_cal0612_2p52VPM_prebias_10_2_dur_87min_flashDCRC_1_4.msl |
| 2052 | Start an 87 min series at HV = 180→400V, rate 2.52V/min, with 10% prebias for 2 minutes, flash at end with 30 min wait. CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (490/400/490)/(420/480/450) uA, Front-End Gains = (2/2/3)/(5/5/5) 1000 BOR, 5Hz InRun, and 1000 EOR randoms, trigger on DCRC1pB/C/D threshold = 10/10/10. Use sequence HVdrift_180V_cal0612_2p52VPM_prebias_10_2_dur_87min_flashDCRC_1_4.msl |
| DCRC4pB was railed for this entire series |