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2013/03/23

1130 Fed Cricket 4 pellets.
1142 Attempted to connect DCRC32 to Dib1 and DCRC33 to Dib2, again signal from Dib2 but not Dib1.
1146 Filled LN2 cold trap full.
1155 Since the fridge temp has dropped to 60mK and G1 and G2 have risen to ~74mbar, we have decided to switch to circulate on cold trap 2. Open V13B, allow mixture to settle and then open 12B. With both cold traps open G1:66.1mbar, G2: 57.3mbar, P1:0.085. Close V13A.
1215 Close c.t. 1 speedivalve and 12A. Open 11A and 8. P1 peaked at ~30mbar.
1230 Attempted to connect DCRC32 to Dib 2, but found no signal. It seems the issue is with board, though an electrical check on Dib1 will confirm this.
1315 IGH has settled. Currently G1: 74.8mbar, G2: 68.0mbar, P1: 0.24mbar (better that the last time we did this (0.65mbar) but not as good as the first time (0.15mbar)), 1K Pot: 1.736K, Fridge: 60.11mK.
1322 Closed V11A and V8. Note that there could still be some mixture in cold trap 1 but it is too difficult to determine by using P1.
1403 Performed electrical check. Results below. Overall few small changes but mostly consistent with similar check done on 2013/03/11. This suggests that the issue lies in the board. Jianjie also performed tests which suggested that the board wasn't functioning properly. In particular it seems that the charge channel amplifiers aren't turning on.
Detector: G101b DIB1 BH: Stripline: 21
SC: ZB1-1-6 60 mK
Face: 2 Date 2012-03-23
SQUET: ZC70 Who AK
Signal Pos. lead Gnd lead Nominal Actual Chassis
(Gnd lead)
Nominal:
< 0.1 nS
Phonon
SQUID bias A/Ret 4 20 80 - 140 open OK
SQUID bias B/Ret 19 34 80 - 140 open OK
SQUID bias C/Ret 8 24 80 - 140 99 OK
SQUID bias D/Ret 23 39 80 - 140 open OK
Feedback A/Ret 37 21 1.0 - 1.3 k 1.5k OK
Feedback B/Ret 2 18 1.0 - 1.3 k open OK
Feedback C/Ret 41 25 1.0 - 1.3 k open OK
Feedback D/Ret 22 6 1.0 - 1.3 k 1.2k OK
QET A/Ret 3 1, 13, 14, 17, 32 20 - 30 open OK
QET B/Ret 35 29, 33, 47, 48 20 - 30 27,26,31,27 OK
QET C/Ret 7 5, 9, 10, 28 20 - 30 open,26,18,26 OK
QET D/Ret 38 36, 40, 43, 44 20 - 30 open OK
QET C/QET A Ret 7 1, 13, 14, 17, 32 open,33,28,31,29
QET C/QET D Ret 7 36, 40, 43, 44 open,open,26,26
Charge
FET heater +/- 45 46 1.0 - 1.1 k 1.23k OK
Qi bias/QET Ret 15 <1 nS OK OK
Qo bias/QET Ret 11 <1 nS OK OK
Qi feedback/Drain/Source 50 16, 31 <1 nS 18,18 OK
Qo feedback/Drain/Source 30 12, 27 <1 nS 19,19 OK
Qi drain 16 chassis <0.1 nS – OK
Qo drain 12 chassis <0.1 nS – OK
Qi source 31 chassis <0.1 nS – OK
Qo source 27 chassis <0.1 nS – OK
FET Tsense +/FET heater- 49 46 — OK
LED 1 42 chassis — –
LED 2 26 chassis — –
Isolation Checks
QET C/Feedback D 18 17 OK
QET C/SQUID bias D 18 30 OK
QET D/Feedback D 29 17 OK
QET D/SQUID bias D 29 30 OK
QET A Ret/QET B Ret 1, 13, 14, 17, 32 29, 33, 47, 48 OK
QET A Ret/Qi feedback 1, 13, 14, 17, 32 38 OK
QET A Ret/Qi drain 1, 13, 14, 17, 32 25 OK
QET D Ret/QET B Ret 36, 40, 43, 44 29, 33, 47, 48 OK
QET D Ret/Qi feedback 36, 40, 43, 44 38 OK
QET D Ret/Qi drain 36, 40, 43, 44 25 OK
1606 Attempted to reconnect DCRC33 to Stripline 19 (Dib2), we are now seeing the flatline we had seen before on DCRC32 to 21, plus a flatline on Phonon D. This board had been set aside after Jianjie had finished his tests. Since it had functioned correctly throughout these tests we can assume that something is wrong with the board's connection to the E box (and thus the striplines and detector) or there is something going wrong with the computer's connection to the board. Jianjie suggested that there might be some sort of capacitance in the stripline(s) that is affecting the boards. He suggested the tests described below.
1653 Test 1: Electrical Test on Dib 2- Results posted below. No significant changes were seen from the test performed on 2013/03/11.
Detector: G101b DIB2
SC: ZB1-1-9 60mK
Face: 5 Date 2013-03-23
SQUET: ZC23 Who AC, SM
Signal Pos. lead Gnd lead Nominal Actual Chassis
(Gnd lead)
Nominal:
< 0.1 nS
Phonon
SQUID bias A/Ret 4 20 80 - 140 107 OK
SQUID bias B/Ret 19 34 80 - 140 97 OK
SQUID bias C/Ret 8 24 80 - 140 105 OK
SQUID bias D/Ret 23 39 80 - 140 95 OK
Feedback A/Ret 37 21 1.0 - 1.3 k 1.3k OK
Feedback B/Ret 2 18 1.0 - 1.3 k 1.3k OK
Feedback C/Ret 41 25 1.0 - 1.3 k 1.3k OK
Feedback D/Ret 22 6 1.0 - 1.3 k 1.3k OK
QET A/Ret 3 1, 13, 14, 17, 32 20 - 30 38,35,31,35,33 OK
QET B/Ret 35 29, 33, 47, 48 20 - 30 33,32,52,32 OK
QET C/Ret 7 5, 9, 10, 28 20 - 30 32,32,21,32 OK
QET D/Ret 38 36, 40, 43, 44 20 - 30 34,32,31,31 OK
Charge
FET heater +/- 45 46 1.0 - 1.1 k 1.27k OK
Qi bias/QET Ret 15 <1 nS OK OK
Qo bias/QET Ret 11 <1 nS OK OK
Qi feedback/Drain/Source 50 16, 31 <1 nS 18,18 OK
Qo feedback/Drain/Source 30 12, 27 <1 nS 19,19 OK
Qi drain 16 chassis <0.1 nS – OK
Qo drain 12 chassis <0.1 nS – OK
Qi source 31 chassis <0.1 nS – OK
Qo source 27 chassis <0.1 nS – OK
FET Tsense +/FET heater- 49 46 — OK
LED 1 42 chassis — –
LED 2 26 chassis — –
1706 Test 2: Test Board DCRC32 without Connecting to E Box- After disconnecting the board from the E box and supplying power to the board we found that the -15V and +15V LEDs were off. These were the same LEDs that were off when DCRC32 was powered on, further suggesting that this board has the same issue as 32.
1740 To expand upon Test 2 above, Jianjie came down to help test DCRC33. Something went wrong during these tests and we had to restart the computer. Upon restarting we found that the -15V and +15V LED's were on for DCRC33. However they went off again after more tests.
1840 Jianjie determined that there is an issue with the negotiation between the power supply and the DCRC boards. Specifically, only 7V is supplied by the power source although the charge channel amplifiers need 15V, and thus they do not turn on. Jianjie was able to correctly power DCRC33 at times, but never DCRC32. We decided to warm up as we will not be able to take any data with the boards as they are.
1900 Begin pumping mixture to the dump. Close V13B, open V9, V5, V12A and the c. t. 1 speedivalve. Stop the 1K Pot by closing the black speedivalve, and closing V4A. Switch to exhaust.
1910 Turn on mixing chamber heater to 10mW. Current Fridge temp: 1.52K, current He level: 52.2%. Using the 2%/hour approximation, we predict that we will run out of He around 20:00 tomorrow.
1942 Filled LN2 cold trap full.
1954 Fed Cricket 4 pellets.