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2019/03/01 (Friday)

Previous Day

Status: Mixture has been cryocleaned several times. Tower crown has been modified to mount LEDs. Tower crown still needs to be cleaned in the ultrasonic cleaner.
Tower assembly
0940 Clean the modified tower crown in warm water in the ultrasonic cleaner for 15 minutes
1000 Find some short 0-80 screws to mount the LEDs
1010 Polish the thermal contact surfaces on the modified tower crown. Also on the tower connector tube.
1020 Resolder wires to LED boards, so they lay flat and point the right way so we can attach them face down on the crown without shorting the connection. Also cover them with kapton to help prevent shorts.

1035 Cover outermost holes on tower crown with copper tape. These are the holes for when you screw the crown to a housing. These had been left open the last few runs.
1045 Mount LEDs on crown. Check electrical connection with meter in diode mode - two look good showing proper voltages, one however is shorted to chassis. Seems that a little sharp point of solder cut through the kapton. Replace the piece of kapton and add a second layer. Now they all look good.
1320 Attach crown with LEDs to tower.
1330 Remove G101c from the source safe, where it has been activating, and move it into cleanroom.
1340 Perform electrical checkout on G101c: same as two days ago. Only 6 channels show continuity which makes sense, all Side2 has been disconnected. Also checked some cross-channel resistances: around 100 Ω. Can use this to assure no continuity between electrode and detector.
1350 Mount detector on tower, DIBs 1/3/4 → IT4 Tower Faces 5/3/1. The 3 crown LEDs are on the same sides as the DIBs.
1420 Mount electrode housing on the tower. Slot for the electrode wire is above DIB4 - we'll connect to DIB4's QETA and QETA return, this is an unused channel (disconnected from Side 2). Check for leakage between electrode and one of the phonon channels: 0.1 nS. (Before putting the electrode on I checked continuity between crystal edge and a phonon channel and got around 200 Ω.
1430 Cover outermost holes of stack lid with copper tape. Another thing we usually neglect.
1445 Attach threaded rods to stack, with tower thermometer mounted on top of the stack.
1455 Check again for leakage between electrode and housing or crystal: both less than 0.2 nS
1500 Cover all stack holes with copper tape. This is essentially unused DIB slots and the screw holes for them. Note that the holes near the corners don't have to be covered because they aren't open to the interior (they are there for pumpout of the screw holes at top and bottom). On one DIB screw hole left a little “tent” to maybe help prevent trapped air during pumpout.
1520 While laying tower on its side accidentally bent, then broke off, DIB socket on DIB3 for qI (pin 12). Luckily this is not used. Need to be more careful.
1535 Solder two of the LED wires to side coax extender Pins 9&10 and plug in below DIB1
1540 Solder the electrode wire to Pins 1&2 (QET A and Return) of another side coax extender. Also solder the third LED to Pin 9 of this extender. Plug in below DIB4.
1555 Attach side coaxes, ST-3-3/ST-3-8/ST-3-10 → DIBs 1/3/4. Leave off screws on the detector side.
1610 Tower electrical check:
Detector G101c DIB 1
side coax ST-3-3 date/who: 2019-03-01 MF & NM
face 5
+lead - lead signal typical previous measured
1 2 QET A 100 to 200 Ω 207 Ω 206 Ω
2 4 QETA-B 100 to 200 Ω 189 Ω 189 Ω
3 4 QET B 100 to 200 Ω 158 Ω 159 Ω
4 6 QETB-C 100 to 200 Ω 188 Ω 188 Ω
5 6 QET C 100 to 200 Ω 197 Ω 195 Ω
6 8 QETC-D 100 to 200 Ω 223 Ω open
7 8 QET D 100 to 200 Ω 175 Ω open
2 8 QETA-D 100 to 200 Ω 232 Ω open
9 chassis LED1 Rforward 8 to 9 MΩ 377 kΩ 800 kΩ
9 chassis LED1 Vforward 1.0 to 1.1 V 2.8 V * 1.12 V
chassis 9 LED1 Rreverse <1 nS 15 mΩ <1 nS
10 chassis LED2 Rforward 8 to 9 MΩ 789 kΩ 800 kΩ
10 chassis LED2 Vforward 1.0 to 1.1 V 1.086 V 1.1 V
chassis 10 LED2 Rreverse <1 nS <1 nS <1 nS
All pins → Ground <1.0nS (Except for LED pins) all <1 nS all <1 nS
Detector G101c DIB 3
side coax ST-3-8 date/who: 2019-03-01 MF & NM
face 3
+lead - lead signal typical previous measured
1 2 QET A 100 to 200 Ω open open
2 4 QETA-B 100 to 200 Ω open open
3 4 QET B 100 to 200 Ω 131 Ω open
4 6 QETB-C 100 to 200 Ω 155 Ω open
5 6 QET C 100 to 200 Ω 138 Ω 139 Ω
6 8 QETC-D 100 to 200 Ω open open
7 8 QET D 100 to 200 Ω open open
2 8 QETA-D 100 to 200 Ω open open
9 chassis LED1 Rforward 8 to 9 MΩ n/a
9 chassis LED1 Vforward 1.0 to 1.1 V n/a
chassis 9 LED1 Rreverse <1 nS n/a
10 chassis LED2 Rforward 8 to 9 MΩ n/a
10 chassis LED2 Vforward 1.0 to 1.1 V n/a
chassis 10 LED2 Rreverse <1 nS n/a
All pins → Ground <1.0nS (Except for LED pins) all <1 nS all <1 nS
Detector G101c DIB 4
side coax ST-3-10 date/who: 2019-03-01 MF & NM
face 1
+lead - lead signal typical previous measured
1 2 QET A 100 to 200 Ω open 59 Ω *
2 4 QETA-B 100 to 200 Ω open open
3 4 QET B 100 to 200 Ω 162 Ω open
4 6 QETB-C 100 to 200 Ω 189 Ω open
5 6 QET C 100 to 200 Ω 200 Ω 201 Ω
6 8 QETC-D 100 to 200 Ω 232 Ω 233 Ω
7 8 QET D 100 to 200 Ω 223 Ω 223 Ω
2 8 QETA-D 100 to 200 Ω open open
9 chassis LED1 Rforward 8 to 9 MΩ 792 kΩ 790 kΩ
9 chassis LED1 Vforward 1.0 to 1.1 V 1.087 V 1.3 V
chassis 9 LED1 Rreverse <1 nS <1 nS <1 nS
10 chassis LED2 Rforward 8 to 9 MΩ 785 kΩ n/a
10 chassis LED2 Vforward 1.0 to 1.1 V 1.082 V n/a
chassis 10 LED2 Rreverse <1 nS <1 nS n/a
All pins → Ground <1.0nS (Except for LED pins) all <1 nS all <1 nS

* This is the two pins that are connected to the electrode.

1620 Also check continuity from DIB4 QET A & Return to Electrode: 30 Ω. Check leakage from electrode to chassis and to a connected phonon channel: both < 1 nS.
1640 Attach 30mK adapter plate. Look carefully for holes to patch for IR shielding. For one hole, cover with “tented” tape for pumpout. Notice gap between plate and tower pin boards - can see it pretty by shining flashlight up with the lights out. Cover these with tape too.
1700 Put completed tower into N2 purge.

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