2018/04/27 (Friday)
| Warming up after discovering short from DIB3 QET A to chassis at 77K (again). He and N2 in cryostat vacuum jacket. | |
| 0950 | Lower main bath |
| 0955 | MC(Cernox) = 282.2 K |
| 1040 | Tower removed. |
| 1045 | Check DIB3 pin1 to chassis at tower level. Open, but if we push on the side coax at the DIB we can make it short. (Shoulda checked that last time.) |
| 1055 | Remove side coax (ST-3-9) from DIB3. Try checking PIN1 to chassis on the detector. It's open, and pushing on the DIB pins doesn't cause a short. Try the side coax instead, pin1 to chassis - pushing on the DIB-side pin causes a short! So it's the side coax. This pin looks shorter than the others. We're guessing that it's gotten pushed in, breaking the solder joint a little, and is touching the copper at the back. |
| Check side coax ST-3-8. I think it has charge-related problems but we checked the phonon and LED wires and they look fine and nothing looks shorted. We'll plug this one into DIB3. | |
| 1100 | Tower electrical check: |
| Detector | S101 | DIB | 1 | |
|---|---|---|---|---|
| side coax | ST-3-3 | date/who: | 2018-04-27 | NM MF |
| face | 5 | |||
| +lead | - lead | signal | typical | previous/now |
| 1 | 2 | QET A | 100 to 200 Ω | 399/393 Ω |
| 2 | 4 | QETA-B | 100 to 200 Ω | 3.1/5.8 kΩ |
| 3 | 4 | QET B | 100 to 200 Ω | 208/205 Ω |
| 4 | 6 | QETB-C | 100 to 200 Ω | OL/6 kΩ |
| 5 | 6 | QET C | 100 to 200 Ω | 492/479 Ω |
| 6 | 8 | QETC-D | 100 to 200 Ω | 4.2/5.6 kΩ |
| 7 | 8 | QET D | 100 to 200 Ω | 375/367 Ω |
| 2 | 8 | QETA-D | 100 to 200 Ω | 3.5/5.8 kΩ |
| 9 | chassis | LED1 Rforward | 8 to 9 MΩ | 150/91 kΩ |
| 9 | chassis | LED1 Vforward | 1.0 to 1.1 V | 1.04/1.036 V |
| chassis | 9 | LED1 Rreverse | <1 nS | 240/270 kΩ |
| 10 | chassis | LED2 Rforward | 8 to 9 MΩ | 800/780 kΩ |
| 10 | chassis | LED2 Vforward | 1.0 to 1.1 V | 1.114/1.119 V |
| chassis | 10 | LED2 Rreverse | <1 nS | 0.2/<1 nS |
| All pins → Ground | <1.0nS | (Except for LED pins) | all <0.5/0.3 nS | |
| Detector | S101 | DIB | 3 | |
|---|---|---|---|---|
| side coax | ST-3-8 | date/who: | 2018-04-27 | NM MF |
| face | 3 | |||
| +lead | - lead | signal | typical | previous/now |
| 1 | 2 | QET A | 100 to 200 Ω | OL/OL Ω |
| 1 | 4 | QETA-B | 100 to 200 Ω | 2.7/4 kΩ |
| 3 | 4 | QET B | 100 to 200 Ω | 129/128 Ω |
| 4 | 6 | QETB-C | 100 to 200 Ω | 3.3/5.5 kΩ |
| 5 | 6 | QET C | 100 to 200 Ω | 132/131 Ω |
| 6 | 8 | QETC-D | 100 to 200 Ω | inf/inf Ω |
| 7 | 8 | QET D | 100 to 200 Ω | inf/inf Ω |
| 2 | 8 | QETA-D | 100 to 200 Ω | inf/inf Ω |
| 9 | chassis | LED1 Rforward | 8 to 9 MΩ | 790/800 kΩ |
| 9 | chassis | LED1 Vforward | 1.0 to 1.1 V | 1.087/1.115 V |
| chassis | 9 | LED1 Rreverse | <1 nS | 0.1/<1 nS |
| 10 | chassis | LED2 Rforward | 8 to 9 MΩ | 790/810 kΩ |
| 10 | chassis | LED2 Vforward | 1.0 to 1.1 V | 1.089/1.116 V |
| chassis | 10 | LED2 Rreverse | <1 nS | 0.3/<1 nS |
| All pins → Ground | <1.0nS | (Except for LED pins) | all <0.3/0.5 nS | |
| Detector | S101 | DIB | 4 | |
|---|---|---|---|---|
| side coax | ST-3-10 | date/who: | 2018-04-27 | NM MF |
| face | 1 | |||
| +lead | - lead | signal | typical | measured |
| 1 | 2 | QET A | 100 to 200 Ω | 457/447 Ω |
| 2 | 4 | QETA-B | 100 to 200 Ω | 4.5/5.7 kΩ |
| 3 | 4 | QET B | 100 to 200 Ω | 525/512 Ω |
| 4 | 6 | QETB-C | 100 to 200 Ω | (flashing OL)/7 kΩ |
| 5 | 6 | QET C | 100 to 200 Ω | 452/442 Ω |
| 6 | 8 | QETC-D | 100 to 200 Ω | 6.1/5.9 kΩ |
| 7 | 8 | QET D | 100 to 200 Ω | 482/471 Ω |
| 2 | 8 | QETA-D | 100 to 200 Ω | flashing OL/6.7 kΩ |
| 9 | chassis | LED1 Rforward | 8 to 9 MΩ | open/open kΩ |
| 9 | chassis | LED1 Vforward | 1.0 to 1.1 V | 1.093/open V |
| chassis | 9 | LED1 Rreverse | <1 nS | 0.4/0.3 nS |
| 10 | chassis | LED2 Rforward | 8 to 9 MΩ | 800/800 kΩ |
| 10 | chassis | LED2 Vforward | 1.0 to 1.1 V | 1.095/1.11 V |
| chassis | 10 | LED2 Rreverse | <1 nS | 0.4/0.3 nS |
| All pins → Ground | <1.0nS | (Except for LED pins) | all <0.2 nS | |
| 1115 | Tower reassembled. Note that we were able to remove the side coax without removing the adapter ring. |
|---|---|
| 1230 | Tower installation underway SQUET plugged in to DIB3. Electrical check: all OK. |
| 1235 | SQUET plugged in to DIB1, electrical check OK |
| 1240 | SQUET plugged in to DIB4, electrical check OK |
| 1305 | IVC sealed. Begin pumping out IVC with scroll pump |
| 1315 | Begin pumping out IVC with turbo pump |
| 1550 | Turbo = 140 nbar. IVC = 25 ubar with turbo valved out. Leak signal very high, 6,000 pbarL/s. Try squirt tests - see it go up a little with big blasts near top of stripline tube, but no leak seen anywhere else. |
| 1615 | Try flushing IVC with some N2. Let 100 mbar N2 into IVC. Then pump it out again with scroll pump, then turbo pump. |
| 1630 | Turbo on IVC is down to 100 nbar. Put leak detector on IVC with turbo still pumping. Leak = 375 pbarL/s. We'll see if it goes down over time. |
| 1640 | Turbo = 74 nbar. Leak = 353 pbarL/s. |
| 1650 | Turbo = 74 nbar. Leak = 336 pbarL/s. |
| 1700 | Turbo = 74 nbar. Leak = 319 pbarL/s. |
| 1705 | Try valving out turbo. Leak → 4870 pbarL/s. |
| 1715 | Return to pumping IVC with turbo |
| Cryocleaning mixture | |
|---|---|
| 1215 | Start cryocleaning mixture through cold LN2 Trap 2, V6 = 12.4% |
| 1230 | Increase V6 → 12.8% to restart flow. |
| 1315 | Stop cryocleaning. Trap 2, 60 minutes |
| 1400 | Start cryocleaning mixture through cold LN2 Trap 1, V6 = 13.0% |
| 1435 | Increase V6 → 13.1% to speed up flow. |
| 1500 | Stop cryocleaning. Trap 1, 60 minutes |