2012/02/21

0040	Taking 07120221_0040_F0001. First of four series at +7V Am-241 data. Data/flash/cooldown = 30/0.1/20 min. Flashed 1 hour before taking data. Trigger on Q1-4 at 40 ADC bins. Will take +10V for four series, +5V two series, and -5V two series. Tower temperature 80mK.
0945	Filled LN2 cold trap.
1145	Data was finished. Raise temperature to 600mK.
1212	07120221_1212_F0001. -10V Am-241 data at 600mK.

# 1 hour flashing before the data below
# +7V Am-241 Data/flash/cooldown = 30/0.1/20 min 80mK
1.7G    07120221_0040
1.7G    07120221_0130
1.7G    07120221_0220
1.7G    07120221_0310
# +10V Am-241 Data/flash/cooldown = 30/0.1/20 min 80mK
1.7G    07120221_0401
1.7G    07120221_0452
1.7G    07120221_0542
1.7G    07120221_0632
# +5V Am-241 Data/flash/cooldown = 30/0.1/20 min 80mK
1.7G    07120221_0723
1.7G    07120221_0813
# -5V Am-241 Data/flash/cooldown = 30/0.1/20 min 80mK
1.7G    07120221_0904
1.6G    07120221_0954
# -10V Am-241 Data/flash/cooldown = 30/0.1/20 min 600mK
3.0G    07120221_1212

1720	Plug in both HV DCRC interface boards and apply negative bias to “ground” electrode (ie. collect electrons). Signs of charge breakdown first seen at -40 V. Complete charge breakdown at -45 V. May be able to take data at -35 V.
1820	Start flashing detector.
1833	Start LHe transfer (11.6%).
1915	Finish LHe transfer (92.8%).
	Stop flashing detector.
1929	Filled LN2 cold trap.
1930	Close V6 and open V14. Stop circulation. Set temperature to 1.5K.
1938	Change PID from (10, 120, 0) to (10, 10, 0).
1946	1.5K is very close to 1K pot temperature. Set temperature to 2K to get a larger temperature gradient.
1950	Close V14, Open V3 and V9 instead so the mixture has to go through the N2 cold trap.
1956	Change PID from (10, 10, 0) to (10, 60, 0) based on the temperature oscillation period.
2002	Temperature overshoots frequently. Change PID from (10, 60, 0) to (5, 60, 0).
2008	T still overshoots. Set PID to (2, 0, 0)
2010	Change IDR heater range to 2mW from 20mW.
2013	T is well below the setting point. Set PID to (10, 0, 0).
2055	Checked U02844 calibration data. At 2K excitation is 2mV rather than 20uV. Now the temperature reading is much more stable.
2101	Using PID (1000, 0, 0), temperature stabilizes at 1.9992K. It good enough to take data. I'll stop the tuning here though could use a better I.
	Final settings: IDR MC heater range 2mW; LS370 PID (1000, 0, 0), heater range 10mA; and IGH settings below.

2111	Temperature rose to 1.9994K slowly. Still good enough to take data.
2130	Tried 5min data and 5min flashing at 2K. Can see clear pulses at 0V but the peak the pulses are rounded a lot. The temperature kept increasing at roughly a constant rate up to 2.07K then dropped when the flashing was done. The cooldown took 6min.

5min flashing and cooldown at 2K

3 min flashing test after the 5min test

2150	3min flashing took 4min to cooldown.
2208	Start taking data 07120221_2206_F0001. -10V bias at 2K with Am-241 source. Data/flash/cooldown = 30/3/5 min. Trigger on Q1-4 at 40ADc bin. Will take 4 series for the bias. Will take data at +10, -8, +8, -6V with the same DAQ settings.