2016/05/18 (Wednesday)
| Status: Fridge warming. Mixture from dump was let into fridge yesterday to facilitate warming. V14, Still gate valve, and Condenser speedivalve open. V9 is closed so some mix is isolated in the 3He pump. | |
| 0910 | Tower (Cernox) = 273 K. Rising at about 0.7 K / hour |
| Open V1 to monitor pressure in fridge. G1 (condenser) = 652 mbar | |
| 0945 | Pump mix back to dump (3He pump on, valves open are Condenser, Still, V1, V3, V5, V9). |
| 1000 | Check pressure in IVC. First pump out lines with scroll pump to 0.016 mbar, then isolate pump and open valves to IVC: IVC = 0.63 mbar. |
| 1100 | G1 (condenser) is pumped down to 1 mbar, P1 (still) pumped down to 0.12 mbar. G2 (dump) = 780 mbar. Close all valves and turn off 3He pump. |
| Resistance from QET biases to ground [kΩ] at 273K | ||||
|---|---|---|---|---|
| PA | PB | PC | PD | |
| DIB1 | 2.1 | 0.6 | 0.5 | 0.5 |
| DIB2 | 0.055 | 0.5 | 0.5 | 0.5 |
| DIB3 | 0.4 | 0.5 | 0.5 | 0.5 |
| 1230 | Enter clean room with SD crystal (USD1) to peform detector-level electrical checkout: |
|---|
| Detector | USD1 | DIB | 1 | |
|---|---|---|---|---|
| date/who: | 2015-05-18 | DS AK | ||
| +lead | - lead | signal | typical | measured |
| 1 | 2 | QET A | 100 to 200 Ω | open |
| 3 | 4 | QET B | 100 to 200 Ω | open |
| 5 | 6 | QET C | 100 to 200 Ω | open |
| 7 | 8 | QET D | 100 to 200 Ω | open |
| 9 | chassis | LED1 Rforward | 8 to 9 MΩ | open |
| 9 | chassis | LED1 Vforward | 1.0 to 1.1 V | - |
| chassis | 9 | LED1 Rreverse | <1 nS | <0.2 nS |
| 10 | chassis | LED2 Rforward | 8 to 9 MΩ | 782kΩ |
| 10 | chassis | LED2 Vforward | 1.0 to 1.1 V | 1.061 V |
| chassis | 10 | LED2 Rreverse | <1 nS | <0.6 nS |
| 11 | 12 | Qo-Qi | 33.4Ω | |
| 12 | 11 | Qi-Qo | 34.7Ω |
| Detector | USD1 | DIB | 2 | |
|---|---|---|---|---|
| date/who: | 2015-05-18 | DS AK | ||
| +lead | - lead | signal | typical | measured |
| 1 | 2 | QET A | 100 to 200 Ω | open |
| 3 | 4 | QET B | 100 to 200 Ω | open |
| 5 | 6 | QET C | 100 to 200 Ω | open |
| 7 | 8 | QET D | 100 to 200 Ω | open |
| 9 | chassis | LED1 Rforward | 8 to 9 MΩ | 758kΩ |
| 9 | chassis | LED1 Vforward | 1.0 to 1.1 V | 1.059V |
| chassis | 9 | LED1 Rreverse | <1 nS | < 1 nS |
| 10 | chassis | LED2 Rforward | 8 to 9 MΩ | open |
| 10 | chassis | LED2 Vforward | 1.0 to 1.1 V | open |
| chassis | 10 | LED2 Rreverse | <1 nS | <0.2 nS |
| 11 | 12 | Qo-Qi | 38.7Ω | |
| 12 | 11 | Qi-Qo | 43.2Ω |
| As done on May 3rd, perform the following cross-channel resistance measurements. Marked DIB1 with piece of kapton tape, so it's more easily identified. |
| q1 | q2 | q3 | q4 | g1 | g2 | chassis | |
|---|---|---|---|---|---|---|---|
| q1 | - | 21.2 | 33.0 | 45.0 | 14.7 | 14.7 | open |
| q2 | - | - | 31.3 | 38.3 | 11.1 | 11.1 | open |
| q3 | - | - | - | 55.1 | 26.0 | 26.0 | open |
| q4 | - | - | - | - | 38.4 | 38.4 | open |
| g1 | - | - | - | - | - | 0.7 | open |
| g2 | - | - | - | - | - | - | open |
| resistances between four charge channels and two ground connections on opposite side |
|||||||
| 1400 | MC (Cernox) = 275.8 K. IVC = 0.74 mbar. |
|---|---|
| 1425 | Add several tube lengths to He exchange gas to IVC (< 1 inHg). |
| 1555 | Adding gas gave a boost to the warming, about 2 K in 20 minutes, but now it seems to be heating about as slowly as before. |
| 1600 | Tower (Cernox) = 278.1 K. That's 41 Fahrenheit, pretty warm now. |