2017/07/07 (Friday)
| Setup: DIB 3/4 → 3.2 MHz filters 2/3 → cable 2/3 → gender changer 3/x → DCRC33(2)/55(1) | |
| 0900 | Lab = 23.1 C, 41% humidity (yesterday we raised the thermostat setpoint by 2 degrees Fahrenheit) |
| 0900 | Tower/MC/Coldplate = 27.8/30.7/179 mK, Still = 1.3 K / 0.060 mbar, G1/G2 = 133/125 mbar, 1K Pot = 1.67 K / 24 mbar. MB = 70.4% |
| 0905 | Fill LN2 cold trap bath |
| 1000 | Discover that there's a wiring error, details here. We thought DIB1 pD was wired to Side2 pB, but it's really wired to Side2 pA. That means Side2 pB is not connected to anything, and there are two DIB channels connected to Side2 pA. These are the two channels that are strongly shorted to chassis. So it's really only 1 channel shorted. |
| 1335 | Erect two walls of the lead/poly shield (East and West). |
| 1345 | Measure event rate: count 134 pulses in 1.0 s = 134 Hz. Compare with Monday, was 148 Hz, so down 14 Hz. Not as good as Run 62, where it looked like the two walls decreased the background by 27 Hz. |
Here are the most recent working SQUID settings:
| SQUET ZC13 | SQUET ZC26 | SQUET ZC39 | ||||||
|---|---|---|---|---|---|---|---|---|
| Run 63 DIB1 = DCRC1 | Run 63 DIB3 = DCRC4 | Run 63 DIB4 = DCRC2 | ||||||
| chan | SQUID bias | Lockpoint | chan | SQUID bias | Lockpoint | chan | SQUID bias | Lockpoint |
| pA | -91.2 | -4.3 | pA | -81.8 | -3.3 | pA | 54.0 | 1.8 |
| pB | -78.8 | -3.3 | pB | -78.3 | -2.9 | pB | 60.3 | 1.8 |
| pC | -82.0 | -4.8 | pC | -85.0 | -3.5 | pC | 74.0 | 3.5 |
| pD | -100. | -2.7 | pD | -85.0 | -5.7 | pD | 85.0 | 5.7 |
Here are the most recent working SQUID settings:
| DIB chan | Side chan | nominal QET bias [uA] |
|---|---|---|
| DIB1 pA | Side1 pD | 50 |
| DIB1 pB | Side1 pF | |
| DIB1 pC | Side1 pE | 55 |
| DIB1 pD | mistake: Side2 pA | |
| DIB3 pA | Side2 pA | 90* |
| DIB3 pB | Side2 pC | 70 |
| DIB3 pC | Side1 pA | |
| DIB3 pD | Side1 pC | 55 |
| DIB4 pA | Side2 pE | 55 |
| DIB4 pB | Side2 pF | 80 |
| DIB4 pC | Side2 pD | 65 |
| DIB4 pD | Side1 pB | 60 |
| *this is the shorted one, acts funny | ||
| 1550 | Disconnect DCRCs, then reconnect all 3 DIBs. Above settings applied, restart MIDAS programs. |
|---|---|
| Setup: DIB 1/3/4 → 3.2 MHz filters 1/2/3 → cable 1/2/3 → gender changer 1/3/4 → DCRC55(1)/X(4)/33(2) | |
| 1605 | Zap SQUIDs on all 3 DCRCs |
| 1620 | It looks like on DCRC4 the charge isn't really working. qI shows a trace but no sign of pulses; qO is railed. The charge “Vlock” settings, whatever those are, were not at 0 originally - they were at 1.31/-0.39 V. On the other DCRCs these have been left at zero. If you set qI to zero it rails. I can't find a setting for qO that doesn't rail, haven't tried hard though. At any rate should probably not use DCRC4 for charge. For one thing I don't know that the charge bias is calibrated on this DCRC as it is on DCRC1&2. |
Same table as before but I've swapped the DCRC connections for DIB3 and DIB4:
| SQUET ZC13 | SQUET ZC26 | SQUET ZC39 | ||||||
|---|---|---|---|---|---|---|---|---|
| Run 63 DIB1 = DCRC1 | Run 63 DIB3 = DCRC2 | Run 63 DIB4 = DCRC4 | ||||||
| chan | SQUID bias | Lockpoint | chan | SQUID bias | Lockpoint | chan | SQUID bias | Lockpoint |
| pA | -91.2 | -4.3 | pA | 81.8 | 3.3 | pA | -54.0 | -1.8 |
| pB | -78.8 | -3.3 | pB | 78.3 | 2.9 | pB | -60.3 | -1.8 |
| pC | -82.0 | -4.8 | pC | 85.0 | 3.5 | pC | -74.0 | -3.5 |
| pD | -100. | -2.7 | pD | 85.0 | 5.7 | pD | -85.0 | -5.7 |
| Setup: DIB 1/3/4 → 3.2 MHz filters 1/2/3 → cable 1/2/3 → gender changer 1/3/4 → DCRC55(1)/33(2)/X(4) | |
| 1635 | Restart MIDAS programs. Zap SQUIDs. |
| 1700 | DCRC4 pA and pB show no pulses and don't respond to changes in settings - weird, because pB and pD are working. Otherwise things look OK. |
| 1705 | Fill LN2 cold trap bath |