LDS HpGe CPAA Apparatus
Setup
6/19/14
Looked at the raw output of both HpGe detectors setup in the LDS.
Their names are Zyad and Tareq.
Zyad is a 90+% efficiency HpGe detector.
The HV on both was set to 2200 by slowing increasing the voltage from zero while keeping the detector output DC offset from exceeding 100 mV. Zyad's DC output is very sensitive in the first 500 Volts or so. Ortec's suggested operating voltage for Zyad +3500 Volts and for Tareq +3000 Volts.
Below are 2 scope pictures of the signal coming directly out of the detectors
The noise level increases on Zyad to 25 +/- 5 mV when the HV is turned off while Tareq's is 12 +/- 5 mV.
7/23/14 Signals observed
After installing the new ceramic collars on each detector, they were cooled down and the signals below were observed.
I noticed there are offsets on the signal coming from output 1 on each detector. Zyad's has a +50 mV offset and Tareq has a -40 mV offset.