2019/04/19 (Friday)
| Status | Room temperature. All mixture in dump. LN2 traps, 4He trap, fridge all pumped out. 1K Pot needle valve closed. Cryostat vacuum jacket pumped out. IVC open, SQUETs removed. |
|---|---|
| 1050 | Perform bench tests on SQUETs. Confirm known and suspected problems, see below: |
| SQUET&channel | Problem seen during run | Problem seen at bench test | Notes |
|---|---|---|---|
| ZC-68 pD | SQUID open | confirmed | |
| ZC-68 pD | FB open | confirmed | |
| ZC-23 pA | SQUID open | confirmed | |
| ZC-23 pB | SQUID too high | SQUID looks fine | |
| ZC-23 pB | Feedback too low | confirmed | 1 kΩ, s/b ~20 kΩ |
| ZC-23 pC | Suspect input coil open | Input coil too high | 200 kΩ, s/b ~14 kΩ |
| ZC-24 pA | SQUID open | confirmed | this channel was used for HV |
| ZC-24 pA | Feedback too high | confirmed | 19 MΩ, s/b ~20 kΩ |
| ZC-24 pA | Input coil open | ||
| ZC-24 pC | SQUID behaves badly | SQUID resistance looks fine | |
| bold indicates problems we suspect were caused by HV up to 400 V this run | |||
SQUETS to use in next run:
- Re-use ZC-68 on DIB1
- For DIB3 need good pC
- For DIB4 need good pC and pD
- The following candidates seem to fit the bill. None have modified shunt resistances though.
- ZC-26, used in iZIP run 63
- ZC-39, used in iZIP run 63
- ZC-13, used in iZIP run 63
- ZC-70, used in many G106a, G114 runs
- advantage to using these SQUETs that were used in previous phonon runs is that we can re-use old SQUID settings.
Here are some Run 63 SQUID settings.
Also Nick has requested that one unused phonon channel have its shunt reduced like the others and have the TES shorted. This can be accomplished by wirebonding from one of the resistor connections to the “sig coil” connection on the SQUID board. The purpose is to study noise - this example would be like running a TES in s/c but with all the tower pin connections removed.
| 1440 | Perform bench test on SQUETs ZC-26 and ZC-13. On ZC-13, pA has problems (open SQUID and Feedback) which might be broken wirebonds, should try to fix. On ZC-26 pB has many problems, and pA's feedback reads too low. So - could use these two SQUETs for DIB3 and DIB4, and also could use ZC-13 pB to do Nick's test channel. |
|---|---|
| 1500 | Remove tower from fridge. Clean 4K shield bottom flange. Noticed that the tape holding the tower thermometer wire to the 30mK can had come completely undone. Wire was touching 100mK can. |
| 1615 | Remove 30mK adapter from tower, and side coax from Face 1 |
| 1630 | Put tower on bench, desolder and remove the electrode wire from Pins 1 and 2 on the side coax extender on Face 1  |
| 1640 | Solder the electrode wire to two millmax pins and plug them into Pins 1 and 2 of Face 2   |
| 1650 | Electrical check between Tower Face 2 pins 1 and 2 (at bottom of tower) to electrode itself (through DIB slot). Each reads about 30 Ω. Resistance between pins 1 and 2 is 58 Ω. |
| 1655 | Reassemble tower. Replace the copper tape strips that seal the gap between the adapter and the side coax boards.  |