Pump downs

Date of pump down	Components	Reason
05/2021	Cold head and poptop	Detector had not been used in years
07/20/2021	Poptop	Detector temp increased (~5 degree increase in ~14 days, according to thermistor)

How to Read HPGe Thermistor

Make sure detector high voltage is turned off

Unplug pre-amp power

Unscrew detector electronics housing (8 screws total)

Arrows pointing to screws on detector electronics housing

Slide electronics housing towards the crystal end of the detector

Slide the sectioned area in the direction of the arrow to expose the thermistor terminals

Turn multimeter to resistance (Ω) setting

Measure resistance across the white/black wires that exit the white nylon 4 pinned terminal

Check resistance in tables below for corresponding detector temperature

Date	Time	Thermistor Measurement (Ω)	Detector Thermal Cycled Between Previous Measurement	Notes
04/13/22	11:45am	241.2	Yes	Detector casing cold to touch, has been cooling down >72hrs
04/13/22	1:50pm	229.3	No
04/14/22	11:26am	176.0	No
06/02/22	11:46am	185.0	No	Cooler was off for a few minutes prior due to detector being moved to other side of room
06/16/22	10:00am	176.8	No	Measured before use of high voltage
06/30/22	11:00am	184.1	No	Shutdown cable measurement of -11.97, change from normal of -11.87V
07/03/22	12:45pm	182.2	No
07/06/22	11:40am	181.7	No	Detector warmed after this measurement in prep for pumpdown
07/21/22	10:50am	177.2	Yes	Poptop pumped down by IAC, chiller turned on 3:50pm 07/20/22
07/21/22	11:00am	176.2	No	Repeat of above
07/21/22	11:30am	174.7	No	Repeat of above
07/21/22	12:30pm	173.4	No	Repeat of above
07/21/22	1:22pm	172.0	No	Repeat of above
07/21/22	2:11pm	171.2	No	Repeat of above
07/21/22	3:30pm	170.3	No	Repeat of above
07/25/22	10:10am	169.5	No	Detector continued to cool over a weekend, shutdown cable = -11.99V
10/27/22	10:55am	181.2	No	Resolution of detector changed from ~1.4KeV FWHM to ~2.1KeV FWHM
11/01/22	10:48am	171.8	Yes	Thermal cycle of detector in attempt to bring temp back down, attempt was successful.