 Mon Mar 23 21:47:40 2020, Laszlo, Calibration, run114 - Xray145 calib Ba133, distance 305mm - LESS NOISE,
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Detector: 145
Source: 133Ba - strong source
Distance: 305mm
Start time: 21:47:20 23.03.2020
Stop time: 22:04:06 23.03.2020
file name: run114_xxxx.lmd
avrg. rate: 950Hz
dead-time: 11%
Uwe reduced the noise on the 145 degree detector as well.
During measurement the oscilloscope remained connected! |
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Mon Mar 23 22:25:41 2020, Laszlo, Calibration, run115 - Xray35 Ba133 d=334mm, Xray90 Lead source, d=167.5mm,
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Simultaneous measurement of Xray35 and Xray90. The dead-time is <3%
Detector: 35
Source: 133Ba - strong source
Distance: 334mm
Detector: 90
Source: Lead source
Distance: 167.5mm: the lead source was measured 3mm width with the source in the middle. Therefore, I set the paper zylinder to ~169mm distance.
Start time: 22:25:22 23.03.2020
Stop time: 00:04:49 24.03.2020
file name: run115_xxxx.lmd
avrg. rate35: 75Hz
avrg. rate90: 55Hz
dead-time: 2%
Uwe reduced the noise on the 145 degree detector as well.
During measurement the oscilloscope remained connected! |
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Tue Mar 24 00:11:35 2020, Laszlo, Calibration, run116 - Xray35 calib AM241, distance 334mm,
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Detector: 35
Source: 241Am
Distance: 334mm
Start time: 00:11:03 24.03.2020
Stop time: 10:01:4224.03.2020
file name: run116_xxxx.lmd
avrg. rate: 20Hz
dead-time: 0% |
Tue Mar 24 10:20:26 2020, Laszlo, Calibration, Pictures of the xray calibration, 
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Tue Mar 24 10:59:18 2020, Jan, Calibration, Sources - Specifications,
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We used the following sources:
Am241 (OM666) [GSI - Uwe]
Reference Activity: 430 kBq
Uncertainty: 3%
Reference Date: 19.09.2006
Ba133 hi (AN-5868) [GSI - Kozuharov]
Reference Activity: 438 kBq
Uncertainty: 3%
Reference Date: 01.06.2019
Ba133 low (OL 918) [GSI - Angela]
Reference Activity: 39.7 kBq
Uncertainty: 3%
Reference Date: 08.09.2006
Pb210 (2015-1552) [GUF - Rene]
Reference Activity: 7.42 (15) kBq
Uncertainty: 0.15/7.42 = 2%
Reference Date: 01.01.2016 |
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Wed Mar 25 14:26:22 2020, Laszlo, Calibration, run111 - Xray90 calib Am241, distance 167.5mm - LESS NOISE,
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Detector: 90
Source: 241Am
Distance: 167.5mm
.Start time: ? 23.03.2020
Stop time:
file name: run111_xxxx.lmd
avrg. rate: 444Hz
dead-time: 5%
Uwe reduced the noise on the 90 degree detector (see elog entry) |
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Thu Mar 26 12:05:22 2020, Laszlo, Calibration, measurement of collimators,
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The measurements were taken by using a caliper ruler, with precision of +/-0.05mm |
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Sun Apr 5 20:34:42 2020, Laszlo, Calibration, Xray energies - 1. calibration, 8x
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30angle: E[keV] = 0.0158507 *ch-2.07456
90angle: E[keV] = 0.01950*ch-2.76
145angle: E[keV] = 0.017988 *ch-1.809
I could identify 2 peaks in the 241Am spectra and 4 peaks in the 133Ba. These peaks are fitted with a gaussian to get their position --> linear energy calibration for the combined (Am+Ba) data sets for each detector. The function I used: E(ch) [keV] = m*ch+b |
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Mon Apr 6 04:39:19 2020, Laszlo, Calibration, 2. Xray energy calibration, 9x
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30angle: E[keV] = 0.015898 *ch-1.91
90angle: E[keV] = 0.0211075*ch-2.39
145angle: E[keV] = 0.01663 *ch-1.758 |
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Mon Apr 6 23:00:51 2020, Laszlo, Calibration, beam energies for 124Xe and 118Te measurements,
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"The e- cooler settings were the same for the 124Xe and 118Te beams" - Sergey --> speed of the ions is the same --> same MeV/u
E_beam = 10.0606MeV/u
The uncertainty on the cooloer values should be asked from Markus/Regina |
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Wed Apr 8 20:06:10 2020, Laszlo, Calibration, Counts in the K-REC peaks,
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3 datasets were investigated:
-124Xe with Scraper (2. Xray calibration parameters needed)
-124Xe without Scraper (2. Xray calibration parameters needed)
-118Te with Scraper (1. Xray calibration parameters needed)
I looked all the 35°, 90° and 145° detector spectra:
-For both Xe measurements all 3 detector signal can be evaluated
-For Te beam one can see only in the 145° detector spectra the Kalpha and K-REC peaks (with high uncertainty). For the 35° probably the detector was simply not sensitive enough for such low beam intensities. For the 90° case, I am much surprised, the peaks supposed to be there the most prominent of all. In the spectra, I maybe can recognize a peak at ~27,8keV, but this is even in best case only the Kalpha peak. At the range of the expected K-REC (~40keV), there is a bit of increase in the background overlying the peak. This background increase is also in the background spectra. Also probably this twisted cables issue between 90° and 145° didn't help much. I think anyhow, that maybe this must have some noise related origin. I can remember that the cables (despite all of our and Uwe's tries) were not well grounded, the noise level was kind of floating.
In general, I would also remark that we can see some peaks >60keV in the background, but these luckily don't disturb us.
To evaluate the Xray spectra I used the following algorithm:
1, for each type of beams I used the list of event numbers in the next entry (to exclude "bad" events)
To get the Kalpha and K-REC and other peaks I used the condition trigger==1 (jet ON)
To get the background spectra, I used trigger==2 (Jet OFF). The background spectra is only used to see that there is no underlying peak structure below K-REC. To subtract count, the background histo was NOT in use.
2, While using a well-suiting number of bins, I plot the JetON and JetOFF histos.
By eye I choose the range of the K-REC peak and the range for the background fit on the JetON histo. Ofc range_bckgnd > range_peak.
Simultaneously, I check on the JetOFF histo that both, in the fit-range and in the peak-range, there should not be any peak structure visible.
3, For the fit-range in JetON histo, excluding the peak-range, I fit a linear function, m*x+b. For each bin in the fit-range I subtract m*bin_center+b value from the bin content. After the subtraction I check if I got spectra looking like a single peak sitting on a zero
line.
4, To get the K-REC counts, I sum together all the bin values for each bin of the subtracted histo within the peak-range. For the error calculation, I use Gaussian error prop. The uncertainty of the JetON histo counts = sqrt(counts). Also for the subtraction I make the
error like delta(m*bin_center+b)= sqrt(m*bin_center+b) instead using the uncertainty of the fit parameters. This second one wont make much sense, since the slope of the linear fit is usually close to 0 --> the errors grow unrealistically big.
Based on the algorithm above I got the following counts:
-124Xe with Scraper:
35°: 174 +/- 15
90°: 21299 +/- 150
145°: 2104 +/- 52
-124Xe without Scraper:
35°: 65 +/- 9
90°: 7792 +/- 91
145°: 728 +/- 31
-118Te_part1 with Scraper:
35°: -
90°: 427 +/- 40
145°: -
-118Te_part2 with Scraper:
35°: -
90°: 741 +/- 48
145°: -
-124Xe_lowRate with Scraper:
35°: -
90°: 2121 +/- 52
145°: - |
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Thu Apr 23 19:09:58 2020, Laszlo, Calibration, theoretical K-REC cross sections , 9x
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Find attached Andrey Surzhykov's calculations for the theta angle in respect to the beam direction (in lab. frame) vs. cross section for 124Xe54+ and 118Te52+.
The calculations made for collision with two H atoms with the accuracy of 1%. There are no molecular corrections done, but these corrections are within 1%.
The photon-emission is symmetrical in the azimuthal phi angle, but asymetric in theta. The K-REC cross section is given for each integer theta angle. The problem is that our 90° and 145° xray detectors cover more integer theta-angles --> The disk shaped entrance window of the Xray-detectors is sliced for each covered theta angles, and the CS values are averaged together with the weights of the area of the corresponding slice. The 35° det had a non-disk shaped slit collimator! Was it aligned vertical or horizontal or random? I assumed that it had a vertical position --> only cs at theta=35° needs to taken into account
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| 90° | 145° | 35°
| | weighted cs_Xe [barn/sr] | 128,444 | 41,967 | 45,550
| | weighted cs_Te [barn/sr] | 118,616 | 38,918 | 41,740
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For the steradian values I calculated the area of the entrance window of the Xray detectors and I divided it with the area of the sphere with radius = distance between source and det. If r=radius of the entrance window, D=distance between source and det.: covered steradian = r^2*pi/(4*pi*D^2) [%], covered steradian = 4Pi*[r^2*pi/(4*pi*D^2)] [4pi]. This is valid for the 90° and 145° Xray detectors. The area of 35° det. was calculated individually.
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| 90° | 145° | 35°
| | sr [%] | 0,00237 | 0,00076 | 0,00002
| | sr [4pi] | 0,0298 | 0,0096 | 0,00030
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I converted barn/sr to barn in the following way: steradian[4pi]*weigthed_cs [barn/sr] = weigthed_cs [barn]. I am not 100% sure if I need here the steradian in [4pi] or in [%].
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| 90° | 145° | 35°
| | weighted cs_Xe [barn] | 3,8247 | 0,4012 | 0,0137
| | weighted cs_Te [barn] | 3,5321 | 0,3720 | 0,0125
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Wed Apr 29 16:06:28 2020, Laszlo, Calibration, efficiency fit - 90degree, combined dataset,
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For the efficiency vs E fit of the 90degree Xray detector I have used the following phenomenological funciton:
f(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d)
Here the first exponent member is a saturation curve. This part describes the passing through of the two Be windows (chamber + before detector) and through the dead layer of Ge crystal. One needs a minimum energy to enter to the detecting Ge crystal = C parameter. b parameter = characteristic absorbtion E of these nondetecting layers.
The second exponent is an exponential decrease of the detector efficiency. Photons with higher energy are less detectable by the germaniums. The d parameter is the characteristic E for hard Xray and gamma (>40keV) detectability.
https://www.amptek.com/internal-products/si-pin-vs-cdte-comparison
//Jan's comment: the tail of this function should more or less follow a linear trend a bit above than 40 keV.
In the attachment there is an example fit for 90 degree with combined 1. and 2. (before and after beamtime) calibration datasets.
I made the fit with gnuplot:
degrees of freedom (FIT_NDF) : 8
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
p-value of the Chisq distribution (FIT_P) : 0.994094
Final set of parameters Asymptotic Standard Error
======================= ==========================
a = 0.00308376 +/- 0.0005144 (16.68%)
c = 15.6259 +/- 2.035 (13.03%)
b = 9.36888 +/- 3.16 (33.73%)
d = 177.141 +/- 84.95 (47.95%)
Laszlo's out. |
 Thu Apr 30 17:40:57 2020, Laszlo, Calibration, efficiency fits,
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For all 3 detector the calibration data sets were combined to include the systematics in the fit results directly. Combining means not a weighted average, just simple all data points were included into the fit --> doubled efficiency value for most of the energies.
The g(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d) function was used to describe the behavior of the Germanium detectors for the whole range of energies (global behavior). From these fits the 80keV outlier point was excluded. This is very strange that it doesn't follow the trend, it would be nice to find out why not.
Between 40-75keV a linear fit was carried out as well. This can also approximate quite well this local energy range, what we need for the K-REC peaks.
l(x) = m*x+e
All the fits were done by gnuplot, but it was also confirmed that ROOT gives us the same parameters + errors + chisquare. One just need to choose well the starting values :)
90° fits:
degrees of freedom (FIT_NDF) : 8
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
p-value of the Chisq distribution (FIT_P) : 0.994094
Final set of parameters Asymptotic Standard Error
======================= ==========================
a = 0.00308376 +/- 0.0005144 (16.68%)
c = 15.6259 +/- 2.035 (13.03%)
b = 9.36888 +/- 3.16 (33.73%)
d = 177.141 +/- 84.95 (47.95%)
degrees of freedom (FIT_NDF) : 4
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.283372
variance of residuals (reduced chisquare) = WSSR/ndf : 0.0802998
p-value of the Chisq distribution (FIT_P) : 0.988405
Final set of parameters Asymptotic Standard Error
======================= ==========================
m = -6.22672e-06 +/- 1.836e-06 (29.48%)
e = 0.00256426 +/- 9.873e-05 (3.85%)
145° fits:
degrees of freedom (FIT_NDF) : 6
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.379472
variance of residuals (reduced chisquare) = WSSR/ndf : 0.143999
p-value of the Chisq distribution (FIT_P) : 0.990247
Final set of parameters Asymptotic Standard Error
======================= ==========================
a = 0.0012346 +/- 0.0006794 (55.03%)
c = 11.3754 +/- 4.075 (35.82%)
b = 15.6961 +/- 13.2 (84.1%)
d = 116.084 +/- 99.83 (86%)
degrees of freedom (FIT_NDF) : 2
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.327728
variance of residuals (reduced chisquare) = WSSR/ndf : 0.107405
p-value of the Chisq distribution (FIT_P) : 0.898161
Final set of parameters Asymptotic Standard Error
======================= ==========================
m = -2.39246e-06 +/- 1.278e-06 (53.42%)
e = 0.000848859 +/- 7.329e-05 (8.634%)
35° fit:
degrees of freedom (FIT_NDF) : 7
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 1.40676
variance of residuals (reduced chisquare) = WSSR/ndf : 1.97896
p-value of the Chisq distribution (FIT_P) : 0.0538635
Final set of parameters Asymptotic Standard Error
======================= ==========================
a = 0.000114396 +/- 0.0002367 (206.9%)
c = 14.3178 +/- 8.322 (58.13%)
b = 16.7454 +/- 43.21 (258%)
d = 79.7991 +/- 173.2 (217.1%)
degrees of freedom (FIT_NDF) : 3
rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 1.21233
variance of residuals (reduced chisquare) = WSSR/ndf : 1.46975
p-value of the Chisq distribution (FIT_P) : 0.220529
Final set of parameters Asymptotic Standard Error
======================= ==========================
m = -3.7879e-07 +/- 3.143e-07 (82.99%)
e = 7.31447e-05 +/- 1.788e-05 (24.45%)
> For the efficiency vs E fit of the 90degree Xray detector I have used the following phenomenological funciton:
>
> f(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d)
>
> Here the first exponent member is a saturation curve. This part describes the passing through of the two Be windows (chamber + before detector) and through the dead layer of Ge crystal. One needs a minimum energy to enter to the detecting Ge crystal = C parameter. b parameter = characteristic absorbtion E of these nondetecting layers.
> The second exponent is an exponential decrease of the detector efficiency. Photons with higher energy are less detectable by the germaniums. The d parameter is the characteristic E for hard Xray and gamma (>40keV) detectability.
>
> https://www.amptek.com/internal-products/si-pin-vs-cdte-comparison
>
> //Jan's comment: the tail of this function should more or less follow a linear trend a bit above than 40 keV.
>
>
> In the attachment there is an example fit for 90 degree with combined 1. and 2. (before and after beamtime) calibration datasets.
> I made the fit with gnuplot:
>
> degrees of freedom (FIT_NDF) : 8
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
> variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
> p-value of the Chisq distribution (FIT_P) : 0.994094
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> a = 0.00308376 +/- 0.0005144 (16.68%)
> c = 15.6259 +/- 2.035 (13.03%)
> b = 9.36888 +/- 3.16 (33.73%)
> d = 177.141 +/- 84.95 (47.95%)
>
> Laszlo's out. |
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Thu Apr 30 22:55:45 2020, Laszlo, Calibration, inverse square law test,
|
I have made also the inverse square law fits. We have data only for 90degre with the 241Am source, but both for the 1. and 2. calibrations. The 1. and 2. calibration data sets treated separate.
2 peaks were investigated, 59.5keV and 26.3keV, at two distances 184.8mm and 217.3mm. These distances are the sum of 4 distances:
a = width of plastic head. uncert.: +/- 0.05mm, measured with caliper.
b = width of the brass collimator. uncert.: +/- 0.05mm, measured with caliper.
c = width of protector plastic ring. uncert.: +/- 0.05mm, measured with caliper.
d= distance of the paper head. uncert: +/- 0.5mm, judged by the eye :)
The Be window and the dead layer of the Ge detector is not taken into account.
The distances calculated as D=a+b+c+d.
The conclusion is that the uncertainty coming from the distance measurements are negligible compared to the other uncertainties. The data obey the inverse square law.
> For all 3 detector the calibration data sets were combined to include the systematics in the fit results directly. Combining means not a weighted average, just simple all data points were included into the fit --> doubled efficiency value for most of the energies.
> The g(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d) function was used to describe the behavior of the Germanium detectors for the whole range of energies (global behavior). From these fits the 80keV outlier point was excluded. This is very strange that it doesn't follow the trend, it would be nice to find out why not.
> Between 40-75keV a linear fit was carried out as well. This can also approximate quite well this local energy range, what we need for the K-REC peaks.
> l(x) = m*x+e
>
> All the fits were done by gnuplot, but it was also confirmed that ROOT gives us the same parameters + errors + chisquare. One just need to choose well the starting values :)
>
>
> 90° fits:
> degrees of freedom (FIT_NDF) : 8
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
> variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
> p-value of the Chisq distribution (FIT_P) : 0.994094
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> a = 0.00308376 +/- 0.0005144 (16.68%)
> c = 15.6259 +/- 2.035 (13.03%)
> b = 9.36888 +/- 3.16 (33.73%)
> d = 177.141 +/- 84.95 (47.95%)
>
> degrees of freedom (FIT_NDF) : 4
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.283372
> variance of residuals (reduced chisquare) = WSSR/ndf : 0.0802998
> p-value of the Chisq distribution (FIT_P) : 0.988405
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> m = -6.22672e-06 +/- 1.836e-06 (29.48%)
> e = 0.00256426 +/- 9.873e-05 (3.85%)
>
>
>
> 145° fits:
> degrees of freedom (FIT_NDF) : 6
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.379472
> variance of residuals (reduced chisquare) = WSSR/ndf : 0.143999
> p-value of the Chisq distribution (FIT_P) : 0.990247
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> a = 0.0012346 +/- 0.0006794 (55.03%)
> c = 11.3754 +/- 4.075 (35.82%)
> b = 15.6961 +/- 13.2 (84.1%)
> d = 116.084 +/- 99.83 (86%)
>
> degrees of freedom (FIT_NDF) : 2
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.327728
> variance of residuals (reduced chisquare) = WSSR/ndf : 0.107405
> p-value of the Chisq distribution (FIT_P) : 0.898161
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> m = -2.39246e-06 +/- 1.278e-06 (53.42%)
> e = 0.000848859 +/- 7.329e-05 (8.634%)
>
>
>
> 35° fit:
> degrees of freedom (FIT_NDF) : 7
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 1.40676
> variance of residuals (reduced chisquare) = WSSR/ndf : 1.97896
> p-value of the Chisq distribution (FIT_P) : 0.0538635
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> a = 0.000114396 +/- 0.0002367 (206.9%)
> c = 14.3178 +/- 8.322 (58.13%)
> b = 16.7454 +/- 43.21 (258%)
> d = 79.7991 +/- 173.2 (217.1%)
>
> degrees of freedom (FIT_NDF) : 3
> rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 1.21233
> variance of residuals (reduced chisquare) = WSSR/ndf : 1.46975
> p-value of the Chisq distribution (FIT_P) : 0.220529
>
> Final set of parameters Asymptotic Standard Error
> ======================= ==========================
> m = -3.7879e-07 +/- 3.143e-07 (82.99%)
> e = 7.31447e-05 +/- 1.788e-05 (24.45%)
>
>
>
> > For the efficiency vs E fit of the 90degree Xray detector I have used the following phenomenological funciton:
> >
> > f(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d)
> >
> > Here the first exponent member is a saturation curve. This part describes the passing through of the two Be windows (chamber + before detector) and through the dead layer of Ge crystal. One needs a minimum energy to enter to the detecting Ge crystal = C parameter. b parameter = characteristic absorbtion E of these nondetecting layers.
> > The second exponent is an exponential decrease of the detector efficiency. Photons with higher energy are less detectable by the germaniums. The d parameter is the characteristic E for hard Xray and gamma (>40keV) detectability.
> >
> > https://www.amptek.com/internal-products/si-pin-vs-cdte-comparison
> >
> > //Jan's comment: the tail of this function should more or less follow a linear trend a bit above than 40 keV.
> >
> >
> > In the attachment there is an example fit for 90 degree with combined 1. and 2. (before and after beamtime) calibration datasets.
> > I made the fit with gnuplot:
> >
> > degrees of freedom (FIT_NDF) : 8
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
> > variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
> > p-value of the Chisq distribution (FIT_P) : 0.994094
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > a = 0.00308376 +/- 0.0005144 (16.68%)
> > c = 15.6259 +/- 2.035 (13.03%)
> > b = 9.36888 +/- 3.16 (33.73%)
> > d = 177.141 +/- 84.95 (47.95%)
> >
> > Laszlo's out. |
|
Wed May 6 23:02:42 2020, Laszlo, Calibration, efficiency values,
|
I have calculated the efficiency values by putting the energies of the K-REC peaks into the phenomenological (empirical) function and into the linear function (see below). The K-REC peak's position I got from a Gaussian-fit on the peak. There are 5 data sets in total:
With 1. E-calibration parameters:
-124Xe low rate measurement
-118Te 1. data set (before cable-swap)
With 2. E-calibration parameters:
-118Te 2. data set (after cable-swap)
-124Xe with scraper
-124Xe without scraper
When using the 1. E-calibration parameters, the obtained K-REC energies were much offset (124Xe_lowRate E_KREC=4.00577e+01keV, 118Te_1dataset: E_KREC=3.70922e+01keV), even though I tried all possible linear combinations of the parameters for 90° and 145°. Therefore, at the end I used the theoretical energies of the K-REC peaks from Thomas's website: http://www-ap.gsi.de/Thomas/ap_html_research/energy/index.php
Most probably, the problem is not with the 1. E-calibration itself (the source measurement looks consistent), but with the changing gate width during these measurements. These problematic data sets I marked with a " * " in the tables.
90°:
|
| 124Xe_wScraper | 124Xe_woScraper | 118Te_wScraper_part1 | 118Te_wScraper_part2 | 124Xe_wScraper_lowRate
| | K-REC E [keV] | 4,6093E+01 | 4,6116E+01 | *4,3241E+01 | 4,3135E+01 | *4,6336E+01
| | g(E_KREC) (phenomenology) | 0,002285 | 0,002285 | *0,002289 | 0,002289 | *0,002284
| | l(E_KREC) (linear) | 0,002277 | 0,002277 | *0,002295 | 0,002296 | *0,002276
| | diff. betw. f(E_KREC) and g(E_KREC) | 0,35% | 0,35% | 0,26% | 0,29% | 0,38%
|
145°:
|
| 124Xe_wScraper | 124Xe_woScraper
| | K-REC E [keV] | 4,1292E+01 | 4,1275E+01
| | g(E_KREC) (phenomenology) | 0,000736 | 0,000736
| | l(E_KREC) (linear) | 0,000750 | 0,000750
| | diff. betw. f(E_KREC) and g(E_KREC) | 1,82% | 1,83%
|
35°:
|
| 124Xe_wScraper | 124Xe_woScraper
| | K-REC E [keV] | 5,2309E+01 | 5,2478E+01
| | g(E_KREC) (phenomenology) | 0,0000532 | 0,0000532
| | l(E_KREC) (linear) | 0,0000533 | 0,0000533
| | diff. betw. f(E_KREC) and g(E_KREC) | 0,15% | 0,13%
|
> I have made also the inverse square law fits. We have data only for 90degre with the 241Am source, but both for the 1. and 2. calibrations. The 1. and 2. calibration data sets treated separate.
> 2 peaks were investigated, 59.5keV and 26.3keV, at two distances 184.8mm and 217.3mm. These distances are the sum of 4 distances:
> a = width of plastic head. uncert.: +/- 0.05mm, measured with caliper.
> b = width of the brass collimator. uncert.: +/- 0.05mm, measured with caliper.
> c = width of protector plastic ring. uncert.: +/- 0.05mm, measured with caliper.
> d= distance of the paper head. uncert: +/- 0.5mm, judged by the eye 
>
> The Be window and the dead layer of the Ge detector is not taken into account.
>
> The distances calculated as D=a+b+c+d.
>
> The conclusion is that the uncertainty coming from the distance measurements are negligible compared to the other uncertainties. The data obey the inverse square law.
>
>
> > For all 3 detector the calibration data sets were combined to include the systematics in the fit results directly. Combining means not a weighted average, just simple all data points were included into the fit --> doubled efficiency value for most of the energies.
> > The g(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d) function was used to describe the behavior of the Germanium detectors for the whole range of energies (global behavior). From these fits the 80keV outlier point was excluded. This is very strange that it doesn't follow the trend, it would be nice to find out why not.
> > Between 40-75keV a linear fit was carried out as well. This can also approximate quite well this local energy range, what we need for the K-REC peaks.
> > l(x) = m*x+e
> >
> > All the fits were done by gnuplot, but it was also confirmed that ROOT gives us the same parameters + errors + chisquare. One just need to choose well the starting values
> >
> >
> > 90° fits:
> > degrees of freedom (FIT_NDF) : 8
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
> > variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
> > p-value of the Chisq distribution (FIT_P) : 0.994094
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > a = 0.00308376 +/- 0.0005144 (16.68%)
> > c = 15.6259 +/- 2.035 (13.03%)
> > b = 9.36888 +/- 3.16 (33.73%)
> > d = 177.141 +/- 84.95 (47.95%)
> >
> > degrees of freedom (FIT_NDF) : 4
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.283372
> > variance of residuals (reduced chisquare) = WSSR/ndf : 0.0802998
> > p-value of the Chisq distribution (FIT_P) : 0.988405
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > m = -6.22672e-06 +/- 1.836e-06 (29.48%)
> > e = 0.00256426 +/- 9.873e-05 (3.85%)
> >
> >
> >
> > 145° fits:
> > degrees of freedom (FIT_NDF) : 6
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.379472
> > variance of residuals (reduced chisquare) = WSSR/ndf : 0.143999
> > p-value of the Chisq distribution (FIT_P) : 0.990247
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > a = 0.0012346 +/- 0.0006794 (55.03%)
> > c = 11.3754 +/- 4.075 (35.82%)
> > b = 15.6961 +/- 13.2 (84.1%)
> > d = 116.084 +/- 99.83 (86%)
> >
> > degrees of freedom (FIT_NDF) : 2
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.327728
> > variance of residuals (reduced chisquare) = WSSR/ndf : 0.107405
> > p-value of the Chisq distribution (FIT_P) : 0.898161
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > m = -2.39246e-06 +/- 1.278e-06 (53.42%)
> > e = 0.000848859 +/- 7.329e-05 (8.634%)
> >
> >
> >
> > 35° fit:
> > degrees of freedom (FIT_NDF) : 7
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 1.40676
> > variance of residuals (reduced chisquare) = WSSR/ndf : 1.97896
> > p-value of the Chisq distribution (FIT_P) : 0.0538635
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > a = 0.000114396 +/- 0.0002367 (206.9%)
> > c = 14.3178 +/- 8.322 (58.13%)
> > b = 16.7454 +/- 43.21 (258%)
> > d = 79.7991 +/- 173.2 (217.1%)
> >
> > degrees of freedom (FIT_NDF) : 3
> > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 1.21233
> > variance of residuals (reduced chisquare) = WSSR/ndf : 1.46975
> > p-value of the Chisq distribution (FIT_P) : 0.220529
> >
> > Final set of parameters Asymptotic Standard Error
> > ======================= ==========================
> > m = -3.7879e-07 +/- 3.143e-07 (82.99%)
> > e = 7.31447e-05 +/- 1.788e-05 (24.45%)
> >
> >
> >
> > > For the efficiency vs E fit of the 90degree Xray detector I have used the following phenomenological funciton:
> > >
> > > f(x) = a * (1-exp(-(x-c)/b)) * exp(-x/d)
> > >
> > > Here the first exponent member is a saturation curve. This part describes the passing through of the two Be windows (chamber + before detector) and through the dead layer of Ge crystal. One needs a minimum energy to enter to the detecting Ge crystal = C parameter. b parameter = characteristic absorbtion E of these nondetecting layers.
> > > The second exponent is an exponential decrease of the detector efficiency. Photons with higher energy are less detectable by the germaniums. The d parameter is the characteristic E for hard Xray and gamma (>40keV) detectability.
> > >
> > > https://www.amptek.com/internal-products/si-pin-vs-cdte-comparison
> > >
> > > //Jan's comment: the tail of this function should more or less follow a linear trend a bit above than 40 keV.
> > >
> > >
> > > In the attachment there is an example fit for 90 degree with combined 1. and 2. (before and after beamtime) calibration datasets.
> > > I made the fit with gnuplot:
> > >
> > > degrees of freedom (FIT_NDF) : 8
> > > rms of residuals (FIT_STDFIT) = sqrt(WSSR/ndf) : 0.419915
> > > variance of residuals (reduced chisquare) = WSSR/ndf : 0.176329
> > > p-value of the Chisq distribution (FIT_P) : 0.994094
> > >
> > > Final set of parameters Asymptotic Standard Error
> > > ======================= ==========================
> > > a = 0.00308376 +/- 0.0005144 (16.68%)
> > > c = 15.6259 +/- 2.035 (13.03%)
> > > b = 9.36888 +/- 3.16 (33.73%)
> > > d = 177.141 +/- 84.95 (47.95%)
> > >
> > > Laszlo's out. |
|
Tue Nov 24 15:35:49 2020, Jan, Calibration, DSSD X/Y channel mapping, 2021
|
During the detector test test measurements with alpha source the allocation of the 16 X- and 16 Y-channels has been checked.
For the following final allocation, it is always assumed that the (horizontal) y-strips are placed to face the beam directly, while the (vertical) x-strips are on the backside.
Now, all cables from the preamp to the ADC/TDCs are either labeled BLACK (= X-strips, pos. signals) or labeled RED (= Y-strips, neg. signals). These red or black connections should be kept consistently in order to ensure a well known orientation of the DSSD during the experiment. The test run Si2_run006.lmd was taken with this final assignment and serves as reference.
BLACK LABEL > X1 to X16 > pos. MSCF > ADC/TDC ch 0-15 > 50 Ohm resistor at preamps HV-input
RED LABEL > Y1 to Y16 > neg. MSCF > ADC/TDC ch 16-31 > neg. bias voltage at preamps HV-input
Additionally, the RED label indicates the section on the preamp to which negative bias voltage should be applied. |
|
Thu Apr 29 20:32:52 2021, Jan Glorius, Calibration, calibration sources, 2021
|
We use the following list of sources for calibration of the Xray detectors:
- 210Pb [40.1 kBq (4%), 01.10.2020 12:00 UTC] SpecSheet
- 241Am_low [40.5 kBq (3%), 01.10.2020 12:00 UTC] SpecSheet
- 241Am_high [389 kBq (3%), 01.10.2020 12:00 UTC] SpecSheet
- 133Ba_low [40.8 kBq (3%), 01.10.2020 12:00 UTC] SpecSheet
- 133Ba_high [404 kBq (3%), 01.10.2020 12:00 UTC] SpecSheet |
|
Thu Apr 29 20:34:09 2021, Jan Glorius, Calibration, run0003 - Xray90 calib Pb210 d=167.5mm, 2021
|
Efficiency calibration in the lab
Detector: GEM1800 - 90 deg
Source: 210Pb
Distance: 167.5mm
Start time: 20:39:54 - 29.04.2021
Stop time: 08:43:58 - 30.04.2021
file name: e127b_run0003.lmd
avrg. rate: 70Hz
dead-time: 1%
Rate spikes every ~2-3 sec. Need to be checked! |
|
Fri Apr 30 09:27:27 2021, Jan Glorius, Calibration, run0004 - Xray90 calib Pb210 d=167.5mm , 2021
|
Efficiency calibration in the lab
Detector: GEM1800 - 90 deg
Source: 210Pb
Distance: 167.5mm
Start time: 9:26:58 - 30.04.2021
Stop time: 9:33:22 - 30.04.2021
file name: e127b_run0004.lmd
avrg. rate: 50Hz
dead-time: 1%
Still rate peaks, further investigations. |
|