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2013/03/10

0010 Mixing chamber temperature has been rising for the last 10 minutes at a decent rate. Mixing chamber temperature is 7.1 K, up from 6.5 K. Hook up helium gas supply to liquid helium dewar to begin fast transfer.
0020 Resume mixture cryocleaning through nitrogen cold trap 2.
0055 Cease helium transfer. Helium liquid level 91.1%.
1430 Cryocleaning stagnated overnight. Open valve V6 on IGH to 14.3%.
Fill N2 cold trap full.
Mixing chamber temperature 19.7 K. It's rather high, but this simply indicates that there is no gross leak. Isolate IVC and start 1 K pot: temperature 1.7 K.
1440 Very quick electrical check for DIB 1 shows that QET D Returns are still connected as are Qi & Qo Feedbacks, Drains & Sources. Qi & Qo biases still read open when checked to QET D/A Returns, but this is expected and probably does not indicate a problem.
1505 Found mixing chamber heater had been left on, hence the higher than normal mixing chamber temperature. Switched mixing chamber heater off: now I'm unsure of whether we have a leak. If we didn't see one at 77 K, and considering that this is an ionisation-only run and we can live with a higher base temperature, chances are we are fine.
1715 Mixing chamber temperature 18.0 K and falling. Temperature of 1 K pot 1.8 K and holding steady. Interrupt cryocleaning and pump mixture into dump in preparation for condensation.
Fed Cricket 4 pellets.
1810 Dump pressure 725 mbar. Mxing chamber temperature 17.4 K. Start manually condensing mixture through nitrogen cold trap 1.
1815 Fill N2 cold trap full.
1830 Poly-lead shield erected around cryostat.
2030 Mixing chamber temperature 11.8 K and falling steadily. Leave 376 mbar of mixture in dump (ie. around 349 mbar in fridge). Continue manual condensation procedure; start opening valve V12A on IGH.
2245 Mixing chamber temperature 6.3 K and falling steadily. Pressures in P1 & P2 at 120 mbar & 115 mbar respectively. Open valve V12A to 100% to end manual condensation procedure. Wait for mixing chamber to cool further.
2355 Conduct electrical check as mixing chamber cools from 4.2 K to 3.6 K. Only change from that at 77 K is the recovery of Feedback A to Return. Otherwise, as far as we can tell, the important channels are still in place.
Detector: G101b DIB1 BH: Stripline: 21
SC: ZB1-1-6 300 K 80K LHe
Face: 2 Date 2012-03-07 Date 2012-03-09 Date 2013-03-10
SQUET: ZC70 Who HC Who HC Who HC
Signal Pos. lead Gnd lead Nominal Actual Chassis Nominal Actual Chassis Nominal Actual Chassis
(Gnd lead) (Gnd lead) (Gnd lead)
Nominal: Nominal: Nominal:
< 0.1 nS < 0.1 nS < 0.1 nS
Phonon
SQUID bias A/Ret 4 20 3 - 5 k open OK 1 - 2 k open OK 80 - 140 open OK
SQUID bias B/Ret 19 34 4.4k OK open OK 80 - 140 open OK
SQUID bias C/Ret 8 24 4.7k OK 1.8k OK 80 - 140 99 OK
SQUID bias D/Ret 23 39 5.2k OK open OK 80 - 140 open OK
Feedback A/Ret 37 21 15 - 25 k 29k OK 9 - 13 k 2.2M OK 1.0 - 1.3 k 1.5k OK
Feedback B/Ret 2 18 25k OK open OK 1.0 - 1.3 k open OK
Feedback C/Ret 41 25 28k OK open OK 1.0 - 1.3 k open OK
Feedback D/Ret 22 6 35k OK 17k OK 1.0 - 1.3 k 1.2k OK
QET A/Ret 3 1, 13, 14, 17, 32 60 - 80 166,151,145,149,147 OK 30 - 40 open OK 20 - 30 open OK
QET B/Ret 35 29, 33, 47, 48 84,83,97,83 OK 42,41,56,42 OK 20 - 30 28,27,43,27 OK
QET C/Ret 7 5, 9, 10, 28 157,85,76,85 OK open,46,37,46 OK 20 - 30 open,27,18,27 OK
QET D/Ret 38 36, 40, 43, 44 93,90,89,90 OK open OK 20 - 30 open OK
QET C/QET A Ret 7 1, 13, 14, 17, 32 110,93,88,91,89 open,52,47,51,48 open,32,27,30,29
QET C/QET D Ret 7 36, 40, 43, 44 90,87,86,87 open,open,46,47 open,open,26,27
Charge
FET heater +/- 45 46 1.0 - 1.1 k 1.07k OK 1.0 - 1.1 k 1.04k OK 1.0 - 1.1 k 1.25k OK
Qi bias/QET Ret 15 24 - 26 nS open (B); 26 (A,C,D) OK < 1 nS OK OK <1 nS OK OK
Qo bias/QET Ret 11 open (B); 26 (A,C,D) OK OK OK <1 nS OK OK
Qi feedback/Drain/Source 50 16, 31 15 - 17 nS 23,23 OK 6 - 8 nS 20,20 OK <1 nS 18,18 OK
Qo feedback/Drain/Source 30 12, 27 23,23 OK 21,21 OK <1 nS 19,19 OK
Qi drain 16 chassis < 0.1 nS – OK < 0.1 nS – OK <0.1 nS – OK
Qo drain 12 chassis – OK – OK <0.1 nS – OK
Qi source 31 chassis – OK – OK <0.1 nS – OK
Qo source 27 chassis – OK – OK <0.1 nS – OK
FET Tsense +/FET heater- 49 46 0.6 - 0.7 V 0.715 OK 0.9 - 1.0 V 1.094 OK — OK
LED 1 42 chassis 1.0 - 1.1 V 1.135 – 1.2 - 1.5 V open – — –
LED 2 26 chassis open – open – — –
Isolation Checks
QET C/Feedback D 18 17 <0.1 nS OK – OK OK
QET C/SQUID bias D 18 30 OK – OK OK
QET D/Feedback D 29 17 OK – OK OK
QET D/SQUID bias D 29 30 OK – OK OK
QET A Ret/QET B Ret 1, 13, 14, 17, 32 29, 33, 47, 48 OK – OK OK
QET A Ret/Qi feedback 1, 13, 14, 17, 32 38 OK – OK OK
QET A Ret/Qi drain 1, 13, 14, 17, 32 25 OK – OK OK
QET D Ret/QET B Ret 36, 40, 43, 44 29, 33, 47, 48 OK – OK OK
QET D Ret/Qi feedback 36, 40, 43, 44 38 OK – OK OK
QET D Ret/Qi drain 36, 40, 43, 44 25 OK – OK OK
Detector: G101b DIB2 BH: Stripline: 19
SC: ZB1-1-9 300 K LN LHe
Face: 5 Date 2013-03-07 Date 2013-03-09 Date 2013-03-10
SQUET: ZC23 Who HC Who HC Who hc
Signal Pos. lead Gnd lead Nominal Actual Chassis Nominal Actual Chassis Nominal Actual Chassis
(Gnd lead) (Gnd lead) (Gnd lead)
Nominal: Nominal: Nominal:
< 0.1 nS < 0.1 nS < 0.1 nS
Phonon
SQUID bias A/Ret 4 20 3 - 5 k 4.4k OK 1 - 2 k 1.6k OK 80 - 140 107 OK
SQUID bias B/Ret 19 34 5.0k OK 2.0k OK 80 - 140 97 OK
SQUID bias C/Ret 8 24 4.6k OK 1.7k OK 80 - 140 105 OK
SQUID bias D/Ret 23 39 4.3k OK 1.6k OK 80 - 140 95 OK
Feedback A/Ret 37 21 15 - 25 k 18k OK 9 - 13 k 7.3k OK 1.0 - 1.3 k 1.3k OK
Feedback B/Ret 2 18 20k OK 8.3k OK 1.0 - 1.3 k 1.3k OK
Feedback C/Ret 41 25 19k OK 7.6k OK 1.0 - 1.3 k 1.3k OK
Feedback D/Ret 22 6 18k OK 7.1k OK 1.0 - 1.3 k 1.3k OK
QET A/Ret 3 1, 13, 14, 17, 32 60 - 80 90,91,85,89,86 OK 30 - 40 51,50,45,48,46 OK 20 - 30 38,37,32,35,34 OK
QET B/Ret 35 29, 33, 47, 48 87,86,100,86 OK 46,45,60,46 OK 20 - 30 33,32,48,32 OK
QET C/Ret 7 5, 9, 10, 28 85,85,75,85 OK 45,45,34,44 OK 20 - 30 32,33,22,32 OK
QET D/Ret 38 36, 40, 43, 44 86,84,84,84 OK 47,44,44,44 OK 20 - 30 34,32,31,32 OK
Charge
FET heater +/- 45 46 1.0 - 1.1 k 1.07k OK 1.0 - 1.1 k 1.04k OK 1.0 - 1.1 k 1.27k OK
Qi bias/QET Ret 15 24 - 26 nS open (A,B,C); 26 (D) OK < 1 nS OK OK <1 nS OK OK
Qo bias/QET Ret 11 open (A,B,C); 25 (D) OK OK OK <1 nS OK OK
Qi feedback/Drain/Source 50 16, 31 15 - 17 nS 23,23 OK 6 - 8 nS 20,20 OK <1 nS 18,18 OK
Qo feedback/Drain/Source 30 12, 27 23,23 OK 20,20 OK <1 nS 19,19 OK
Qi drain 16 chassis < 0.1 nS – OK < 0.1 nS – OK <0.1 nS – OK
Qo drain 12 chassis – OK – OK <0.1 nS – OK
Qi source 31 chassis – OK – OK <0.1 nS – OK
Qo source 27 chassis – OK – OK <0.1 nS – OK
FET Tsense +/FET heater- 49 46 0.6 - 0.7 V 0.725 OK 0.9 - 1.0 V 1.092 OK — OK
LED 1 42 chassis 1.0 - 1.1 V 1.137 – 1.2 - 1.5 V 1.414 – — –
LED 2 26 chassis 1.13 – 1.404 – — –