 Sun Mar 15 17:13:21 2020, Laszlo, Jan, Calibration, the x-ray gate issue, 
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We found a strange behaviour of our ADC gates for the x-ray detectors.
The setting as shown in the foto below corresponds to a delay of 5 us and a gate length of 15 us.
This is the only setting that produces nice spectra, even though the signals and gate are not aligned.
The setting is extremely sensitive to the delay 4 us still works but 3 or 7 us give already reduced energy values and beyond these values the spectra disapears.
For now it was decided to operate with this not-understood settings because the result is pretty good...
However, further investigation to understand whats happening would be desirable.
Additional note:
This effect appeared after using the new ortec SpecAmps. Before this we used old Tennelec Amps which delivered horrible resolution, but the gates and signals could be matched as expected at this time. |
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Sun Mar 15 17:14:08 2020, Laszlo, Calibration, run036 - Xray90 calib Am241, distance 200!,
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Detector: 90
Source: Am241
Distance: 200mm
Start time: 17:15:12 15.03.2020
Stop time: 17:32:17 15.03.2020
file name: run036_xxxx.lmd
avrg. rate: 450Hz
dead-time: 5% |
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Sun Mar 15 17:33:17 2020, Laszlo, Calibration, run037 - Xray90 calib Am241,
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Detector: 90
Source: Am241
Distance: 167.5mm
Start time: 17:40:00 15.03.2020
Stop time: 17:49:57 15.03.2020
file name: run037_xxxx.lmd
avrg. rate: 620Hz
dead-time: 7%
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update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors. |
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Sun Mar 15 17:50:42 2020, Laszlo, Calibration, run038 - Xray90 calib Ba133, high rate,
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Detector: 90
Source: Ba133 - high rate
Distance: 167.5mm
Start time: 17:53:38 15.03.2020
Stop time: 18:05:41 15.03.2020
file name: run038_xxxx.lmd
avrg. rate: 2.6kHz
dead-time: 26%
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update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors. |
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Sun Mar 15 18:09:19 2020, Laszlo, Calibration, run039 - Xray90 calib Ba133,
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Detector: 90
Source: Ba133
Distance: 167.5mm
Start time: 18:10:02 15.03.2020
Stop time: 18:47:36 15.03.2020
file name: run039_xxxx.lmd
avrg. rate: 150Hz
dead-time: 2% |
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Sun Mar 15 18:53:42 2020, Laszlo, Calibration, run040 - Xray145 calib Am241,
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Detector: 145
Source: Am241
Distance: 305mm
Start time: 18:53:16 15.03.2020
Stop time: 19:18:35 15.03.2020
file name: run040_xxxx.lmd
avrg. rate: 230Hz
dead-time: 3%
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update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors. |
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Sun Mar 15 19:22:58 2020, Laszlo, Calibration, run041 - Xray145 calib Ba133 - high rate,
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Detector: 145
Source: Ba133
Distance: 305mm
Start time: 19:22:34 15.03.2020
Stop time: 19:38:44 15.03.2020
file name: run041_xxxx.lmd
avrg. rate: 1kHz
dead-time: 11%
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update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors. |
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Sun Mar 15 19:46:34 2020, Laszlo, Calibration, run042 - Xray35 calib Ba133 - high rate,
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Detector: 35
Source: Ba133, strong source
Distance: 334mm
Start time: 19:46:54 15.03.2020
Stop time: 20:20:14 15.03.2020
file name: run042_xxxx.lmd
avrg. rate: 60Hz
dead-time: 1% |
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Sun Mar 15 20:26:08 2020, Laszlo, Calibration, run043 - Xray35 calib Am241,
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Detector: 35
Source: Am241
Distance: 334mm
Start time: 20:25:48 15.03.2020
Stop time: 20:56:56 15.03.2020
file name: run043_xxxx.lmd
avrg. rate: 20Hz
dead-time: ~0%
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update at 05.05.2020: the cables were probably twisted between the 90 and the 145 angle detectors. |
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Sun Mar 15 21:01:23 2020, Laszlo, Calibration, run044 - Xray35 calib Ba133 - a night long run ,
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Detector: 35
Source: Ba133
Distance: 334mm
Start time: 21:01:26 15.03.2020
Stop time: 7:11:07 16.03.2020
file name: run044_xxxx.lmd
avrg. rate: 60Hz
dead-time: 1-2%
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update at 05.04.2020: the cables were probably twisted between the 90 and the 145 angle detectors. However, the id of the detector doesnt change, since there were no simultanious measurements (one source used with one detector a detector at a time) |
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Mon Mar 16 15:15:22 2020, Jan, Calibration, Gamma- and X-ray intensities for efficiency calib,
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Intensities for special gamma or x-ray lines needed for efficiency calibration can be found here:
ENSDF
https://www.nndc.bnl.gov/ensdf/#
NUDAT
https://www.nndc.bnl.gov/nudat2/
An old but still usefull data base:
http://nucleardata.nuclear.lu.se/toi/nucSearch.asp |
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Fri Mar 20 19:37:43 2020, Jan, Calibration, Xray energies - rough 1. calibration ,
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-- E calibration seems to have changed! ---
This calibration is based on the source data taken before the experiment:
Xray1: E [keV] = ch*0.01582-1.963
Xray2: E [keV] = ch*0.01799-1.803
Xray3: E [keV] = ch*0.01941-2.618 |
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Mon Mar 23 15:48:15 2020, Laszlo, Calibration, run105 - Xray90 calib Am241, distance 167.5mm, wrong?,
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Detector: 90
Source: Am241
Distance: 167.5mm
Start time: 15:46:49 23.03.2020
Stop time:
file name: run105_xxxx.lmd
avrg. rate: 610Hz
dead-time: 7.5%
suspiciously not Gaussian shaped peaks --> investigation with oscilloscope |
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Mon Mar 23 16:17:58 2020, Laszlo, Calibration, run106 - garbage!,
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run106 was clicked by accident, please delete! |
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Mon Mar 23 16:21:33 2020, Laszlo, Calibration, run107 - Xray90 calib Am241, distance 167.5mm,
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Detector: 90
Source: Am241
Distance: 167.5mm
Start time: 15:46:49 23.03.2020
Stop time: 17:32 23.03.2020
file name: run107_xxxx.lmd
avrg. rate: 610Hz
dead-time: 7%
not Gaussian shaped peaks, after previous investigations with the scope, the scope is disconnected.
Just to mention, in order to improve deadtime the other two Xray dets are disconnected. |
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Mon Mar 23 17:32:42 2020, Laszlo, Calibration, run108 - Xray90 calib Ba133, distance 167.5mm - high rate - deadtime too high!,
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Detector: 90
Source: Ba133 - strong source
Distance: 167.5mm
Start time: 17:32:11 23.03.2020
Stop time: 17:35:34
file name: run108_xxxx.lmd
avrg. rate: 2.7kHz
dead-time: 26% |
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Mon Mar 23 17:40:33 2020, Laszlo, Calibration, run109 - Xray90 calib Ba133, distance 167.5mm -low rate,
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Detector: 90
Source: Ba133 - weak source
Distance: 167.5mm
Start time: 17:40:11 23.03.2020
Stop time:
file name: run109_xxxx.lmd
avrg. rate: 170Hz
dead-time: 2% |
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Mon Mar 23 18:17:27 2020, Laszlo, Calibration, run110 - Xray90 calib Ba133, distance 167.5mm -low rate - LESS NOISE,
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Detector: 90
Source: Ba133 - weak source
Distance: 167.5mm
Start time: 18:14:50 23.03.2020
Stop time:
file name: run110_xxxx.lmd
avrg. rate: 160Hz
dead-time: 2%
Uwe reduced the noise on the 90 degree detector (see previous elog entry) |
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Mon Mar 23 19:32:53 2020, Laszlo, Calibration, run112 - Xray90 calib Am241, distance 200mm - LESS NOISE,
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Detector: 90
Source: 241Am
Distance: 200mm
Start time: 20:01:43 23.03.2020
Stop time:
file name: run112_xxxx.lmd
avrg. rate: 444Hz
dead-time: 5%
Uwe reduced the noise on the 90 degree detector (see elog entry) |
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Mon Mar 23 20:52:37 2020, Laszlo, Calibration, run113 - Xray145 calib Am241, distance 305mm - LESS NOISE,
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Detector: 145
Source: 241Am
Distance: 305mm
Start time: 20:01:43 23.03.2020
Stop time: 21:43:34
file name: run113_xxxx.lmd
avrg. rate: 220Hz
dead-time: 2.5%
Uwe reduced the noise on the 145 degree detector as well. |