Today several tests (3) were done with the germanium detectors with the voltage configuration listed in the previous entry.
The tests were as follows:
Tests with 60Co+137Cs sources
1. Initial evaluation of calibration and resolution (Calibration60Co137Cs_energySignal.root)
2. Cable changes to optimize resolution for detector D4 (Calibration60Co137Cs_timingSignal.root)
Test with 152Eu
3. Final (proposed) configuration of filter parameters, voltages, and cable connections. (Calibration152Eu.root)
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At the time of this log the evaluation of resolution and calibration based on Eu data is to be completed.
The configuration file for the Ge is listed in FirsttestGe.xlsx .
The details of the tests can be found in the attached .pdf pictures or in the .root files.
You may notice that 2/4 of each clover count less than the other 2 and this is due to source position.
For the runs on Co and Cs It was seen that D4 had considerable tailing in channels 1 and 3 (black and green leaves, respectively) and D4 has worse resolution. Channel 3 (green) also requires a non-linear calibration. Currently only linear calibration is applied. But this is as expected from how the detectors were running before leaving Tennessee.
Therefore we decided to check if the second group of signal cables had better resolution for detector D4. The second group of cables were presumed to be timing signals and the run is labeled as such, however, the signals are similar within a few percent and this assumption may have been incorrect.
The result is listed in calibrationClovers.ods in the third tab (TimingvsEnergy).
!!!Noise in the different groups of cables should be evaluated.!!!
Based on this test the first cable from the first test in D4 was reattached and the others remain in place. The second channel saw improvement and the 3rd and 4th channels saw limited change (deemed insignificant). This bundle has been labeled 'D4 Signal' for now.
Avg. D4 Resolution for Co and Cs lines is 3.3 keV FWHM
Avg. G7 Resolution for Co and Cs lines is 2.6 keV FWHM
We estimate that these are accurate within ~10%. But this is sufficient analysis for this point and time.
Further details will be posted regarding the Eu data , at a glance the configuration is seen to be very close except for the known non-linearity in D4 and one channel from G7 which should definitely be recalibrated. Thresholds and noise levels should also be re-evaluated.
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