2011-04-25

0948	Filled N2 cold trap. MC X12004 88.5K. Temperature dropped 20K in the past 4 hours. IVC pressure 0.54mBar. The temperature dropping rate seems a bit slow. But the exchange gas pressure should be good enough, same as in the last run(?).
1215	Switch from cold trap 2 to cold trap 1 to facilitate cleaning of cold trap 2.
	Mixing chamber temperature 83.0 K.
1525	Pump out N2 exchange gas.
	Mixing chamber temperature 79.6 K.
1625	Stop evacuating IVC at pressure 4E-6 mbar. Background He leak rate 3.6E-9 mbar l/s, rising very slowly.
	Start blowing out LN2.
1700	Fill N2 cold trap full.
1740	LN2 out of main dewar. He leak rate rose steadily to 1.2E-8 mbar l/s: a bit high, but no spike so no significant leak.

Electrical Check at 77 K

1755	Perform electrical check. Mixing chamber temperature 78.9 K.

Signal	Pos. lead	Gnd lead	Nominal	Actual	Chassis	Nominal	Actual	Chassis
Detector:	G42 DIB1		BH:			Stripline:	20
SC:	ZB1-1-9		300 K			LN
Face:	5		Date	2011-04-23		Date	2011-04-25
SQUET:	ZC70		Who	HC & JZ		Who	HC & JZ
					(Gnd lead)			(Gnd lead)
					Nominal:			Nominal:
					< 0.1 nS			< 0.1 nS

SQUID bias A/Ret	4	20	3 - 5 k	4.9	OK	1 - 2 k	1.96	OK
SQUID bias B/Ret	19	34		4.4	OK		1.7	OK
SQUID bias C/Ret	8	24		4.7	OK		1.82	OK
SQUID bias D/Ret	23	39		5.3	OK		2.09	OK

Feedback A/Ret	37	21	15 - 25 k	29.4	OK	9 - 13 k	15	OK
Feedback B/Ret	2	18		25.6	OK		9.2	OK
Feedback C/Ret	41	25		28.6	OK		4.2	OK
Feedback D/Ret	22	6		34.8	OK		17.4	OK

QET A/Ret	3	1, 13, 14, 17, 32	60 - 80	79.5,81.2,79.2,80.1,80.1	OK	30 - 40	43,44,42,43,43	OK
QET B/Ret	35	29, 33, 47, 48		76,76,79,76	OK		37,37,40,37	OK
QET C/Ret	7	5, 9, 10, 28		78, 77, 69, 77	OK		41,41,33,40	OK
QET D/Ret	38	36, 40, 43, 44		81, 80, 80, 80	OK		44,43,43,43	OK


FET heater +/-	45	46	1.0 - 1.1 k	1.06	OK	1.0 - 1.1 k	1.04	OK

Qi bias/QET Ret	15		24 - 26 nS	39MΩ	OK	< 1 nS	OK	OK
Qo bias/QET Ret	11			39MΩ	OK		OK	OK

Qi feedback/Drain/Source	50	16, 31	15 - 17 nS	43.5MΩ, 43.5Ohm	OK	6 - 8 nS	50MΩ, 50MΩ	OK
Qo feedback/Drain/Source	30	12, 27		43.6MΩ, 43.6MΩ	OK		50MΩ, 50MΩ	OK

Qi drain	16	chassis	< 0.1 nS	–	OK	< 0.1 nS	–	OK
Qo drain	12	chassis		–	OK		–	OK
Qi source	31	chassis		–	OK		–	OK
Qo source	27	chassis		–	OK		–	OK

FET Tsense +/FET heater-	49	46	0.6 - 0.7 V	0.7	OK	0.9 - 1.0 V	1.084	OK
LED 1	42	chassis	1.0 - 1.1 V	1.13	–	1.2 - 1.5 V	1.411	–
LED 2	26	chassis		1.12	–		1.403	–

Signal	Pos. lead	Gnd lead	Nominal	Actual	Chassis	Nominal	Actual	Chassis
Detector:	G42 DIB2		BH:			Stripline:	19
SC:	ZB1-1-6		300 K			LN
Face:	2		Date	2011-04-23		Date	2011-04-25
SQUET:	ZC23		Who	HC & JZ		Who	HC & JZ
					(Gnd lead)			(Gnd lead)
					Nominal:			Nominal:
					< 0.1 nS			< 0.1 nS

SQUID bias A/Ret	4	20	3 - 5 k	4.4	OK	1 - 2 k	1.63	OK
SQUID bias B/Ret	19	34		5	OK		1.99	OK
SQUID bias C/Ret	8	24		4.6	OK		1.73	OK
SQUID bias D/Ret	23	39		4.3	OK		1.58	OK

Feedback A/Ret	37	21	15 - 25 k	19	OK	9 - 13 k	7.3	OK
Feedback B/Ret	2	18		21	OK		8.2	OK
Feedback C/Ret	41	25		19	OK		7.6	OK
Feedback D/Ret	22	6		18	OK		8.1	OK

QET A/Ret	3	1, 13, 14, 17, 32	60 - 80	85, 87, 85, 86, 86	OK	30 - 40	44,46,44,45,46	OK
QET B/Ret	35	29, 33, 47, 48		86, 86, 89, 86	OK		45,44,47,44	OK
QET C/Ret	7	5, 9, 10, 28		86, 85, 75, 85	OK		45,45,34,44	OK
QET D/Ret	38	36, 40, 43, 44		85, 84, 84, 84	OK		45,44,44,44	OK


FET heater +/-	45	46	1.0 - 1.1 k	1.069	OK	1.0 - 1.1 k	1.044	OK

Qi bias/QET Ret	15		24 - 26 nS	38MΩ	OK	< 1 nS	OK	OK
Qo bias/QET Ret	11			38MΩ	OK		OK	OK

Qi feedback/Drain/Source	50	16, 31	15 - 17 nS	43MΩ, 43MΩ	OK	6 - 8 nS	49MΩ, 49MΩ	OK
Qo feedback/Drain/Source	30	12, 27		43MΩ, 43MΩ	OK		49MΩ, 49MΩ	OK

Qi drain	16	chassis	< 0.1 nS	–	OK	< 0.1 nS	–	OK
Qo drain	12	chassis		–	OK		–	OK
Qi source	31	chassis		–	OK		–	OK
Qo source	27	chassis		–	OK		–	OK

FET Tsense +/FET heater-	49	46	0.6 - 0.7 V	0.721	OK	0.9 - 1.0 V	1.091	OK
LED 1	42	chassis	1.0 - 1.1 V	1.138	–	1.2 - 1.5 V	1.417	–
LED 2	26	chassis		1.128	–		1.407	–

1800	Pump mixture into dump in preparation for throughput test.
	Pump out main bath.
1815	Background He leak rate 1.3E-8 mbar l/s. Start throughput test.
	Throughput test yields rate of 43 mbar/min. Pump mixture into dump.
	No significant change in He leak rate: no leak from mixing chamber pipes to IVC.
1830	Pump out helium transfer stick.
1850	Stop pumping helium transfer stick.
1910	Evacuate 1 K pot.
1930	Overpressurise main bath with He gas. Background leak rate 9.1E-9 mbar l/s. He leak rate drops a little to 8.9E-9 mbar l/s: no leak.
1940	Fill IVC with 0.12 mbar He-4 exchange gas.
2000	Start first LHe transfer.
2053	MX X12004 was 43K while He level > 22%. Hassan said he put in 0.12mbar exchange gas before transfer. This should be good. Maybe the transfer was too fast. IVC pressure 2.2e-2 mbar. Temperature still drops kind of linearly.
2140	Stop LHe transfer. Main bath 97.6% full. Mixing chamber temperature 10.7 K and falling fast. Slope is still fairly linear.
2150	Pump out He-4 exchange gas. Mixing chamber temperature 8.0 K.
2220	Fill N2 cold trap full.
	Start cryocleaning mixture through cold trap 1. Valve 6 open 13.8%. Leave running overnight.
	Open valves 8 and 11b to pump out any remaining mixture in cold trap 2. Leave open overnight.