2017/08/17 (Thursday)

Previous Day

Status	Fridge warming, bath empty. LN2 traps empty and warm. Mixture pumped out of fridge to dump (LHe cold trap isolated at around 20 K). 1K Pot needle valve open. No longer pumping on IVC.
0925	MC (Cernox) = 215.9 K
1020	IVC = 5.4 mbar.
1055	Let 22 “Hg nitrogen into IVC. Should be close to 1 bar when it gets to room temperature (currently MC(Cernox) = 217.5 K) MC temperature starts to rise more quickly. (actually it was a temporary uptick, warming rate pretty much went back to normal after 20 minutes)
1100	G1 pressure has risen to ~100 mbar. Not sure where this comes from but I think I've seen it before. Pump this gas to the dump.
1110	G2(Dump) = 785.5 mbar but still creeping up. Stop the pump.
1115	Open V1 to connect the LHe trap to G1. G1 goes up about 2 mbar. (It will be interesting on some run to try to stop pumping out the mixture and isolate the trap before the H2 boiling point.)
1125	Pump the LHe trap contents out with scroll pump
1130	Open fridge to G1. V1 is open, next open Condenser speedivalve, V3, Still gate valve. Looks like there was maybe 3 mbar in the P1 volume and no more than 1 mbar in the fridge. Pump this out to atmosphere with scroll pump.
1405	G1 flat at 1.6 mbar, P1 nearly flat at 0.07 mbar. Stop pumping out fridge.
1410	Open warm LN2 Trap 1 to G1: 343 mbar. Last run it was >1bar but that was a much longer run. Pump out Trap 1 with scroll pump.

note	As noted previously, the new 6inch detector (S1502) was housed in such a way that the bond pads weren't aligned with the DIB pads. We decided to flip the crystal in the housing, which also requires reversing the order of vacuum electrode and detector in the stack. But we only have one set of side coaxes of a particular length, which need to plug into the detector housing. So we have designed and ordered a new tower connector spool, shorter than the other one, so that the tower-detector distance remains the same.
1500	Flipped the detector in its housing.

note

As noted previously, the new 6inch detector (S1502) was housed in such a way that the bond pads weren't aligned with the DIB pads. We decided to flip the crystal in the housing, which also requires reversing the order of vacuum electrode and detector in the stack. But we only have one set of side coaxes of a particular length, which need to plug into the detector housing. So we have designed and ordered a new tower connector spool, shorter than the other one, so that the tower-detector distance remains the same.

1500

Flipped the detector in its housing.


Lid removed	Lid and crown removed


Support made of foam disks covered with lint-free cloth wipe		Detector on support (pattern side up)


Remove clamps on top	Lower housing	Flip crystal

Each clamp was accompanied by two copper spacers (seemed to all be of equal thickness). Care was taken to make sure crystal was sitting properly in the clamps.


Raise housing (pattern side down)		Attach clamps


Attach clamps

Flip detector so pattern-side is up, then loosen clamps to adjust the rotation of the crystal so that pads line up well. Then tighten all clamps.

1610	Put detector back in purge.

Next Day