![Page 1: Absolute light output determination of crystal scintillators Presented by Min Jeong Kim](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e3a5503460f94b2c75f/html5/thumbnails/1.jpg)
Absolute light output determination of crystal scintillators
Presented by Min Jeong Kim
![Page 2: Absolute light output determination of crystal scintillators Presented by Min Jeong Kim](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e3a5503460f94b2c75f/html5/thumbnails/2.jpg)
Contents
Large Area Avalanche Photodiode Experimental Setup
APD Optimization Test
CsI(Tl) and newly developed crystal test
Conclusion
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Large Area Avalanche photodiode
<Windowless LAAPD>
Model 630-70-73-510
Diameter 16mm
window Windowless
Enhancement UV
Gain 130 at 2600 V
Dark current 110 nA
Capacitance 110 pF
The quantum efficiency close to the 80% in the visible and near infra-red. (PMT ~20%)
Gain of up to several hundred in the total collected charge is possible.
(Photodiode doesn’t have internal gain)
![Page 4: Absolute light output determination of crystal scintillators Presented by Min Jeong Kim](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e3a5503460f94b2c75f/html5/thumbnails/4.jpg)
CsI(Tl) & Experimental setup
slightHygroscopicity
550Peak Emission (nm)
~1050Decay Time (ns)
4.53Density (g/cm3)
40000~60000Light output (Photons/MeV)
valueproperty
<Properties of CsI(Tl) made by Bicron>
PreAmp Amplifier FADC 25MHz
PC
HV
(1800V)
APDcrystal PreAmpPreAmp AmplifierAmplifierFADC
25MHzFADC
25MHz
PCPCHV
(1800V)
HV
(1800V)
APDcrystalAPDcrystal
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APD optimization test
Energy resolution from different gain by changing high voltage.
The best resolution is obtained between 1780V and 1820V.
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APD optimization test
Energy resolution from different shaping time.
The best resolution is obtained with 3~4μs shaping time.
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Energy resolution of CsI(Tl)
Energy resolution (FWHM)
:4.7%
If we use PMT, energy resolution is about 7%
<HV:1800, gain:20 and shaping time:4us in amplifier>
662 keV
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Calibration
EE
E
P
PY
ion
rayX
rayX
peakhe
1
The number of e-h pairs : 37,000 e-h/MeV The absolute light output : 52,000 ph/MeV
<HV:1800, gain:100 and shaping time:4us in amplifier>
EQR
YY
PTFE
heAPDph .
1,
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CsI(Tl) from Yangyang
CsI(Tl)_1
CsI(Tl)_2
47,000 ph/MeV73,000 ph/MeV
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SrCl2 crystal test
Energy resolution (FWHM) : 9.6% The number of e-h pair : 14,000 e-h/MeV The absolute light output : 20,000 ph/MeV
662 keV
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Ba0.20Sr0.80Cl2 crystal test
Energy resolution (FWHM) : 5.4% The number of e-h pair : 16,500 e-h/MeV The absolute light output : 23,000 ph/MeV
662 keV
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Conclusion
The best resolution of CsI(Tl) is obtained with 3~4 μs shaping time, and with 1800V high voltage of LAAPD.
We can measure the number of e-h pairs and the absolute light yield of scintillation crystals with LAAPD.
The number of e-h pair of CsI(Tl) is obtained to be about 37,000 e-h/MeV and the absolute light output is obtained to be about 52,000 ph/MeV for 662 keV 137Cs γ-ray source.
We estimate the relative light output of newly developed SrCl2 crystal to be about 40% of CsI(Tl) and Ba0.20Sr0.80Cl2 crystal to be about 45% of that.
We measured the absolute light yield of ZnSe(O), CeBr3 and other scintillation crystals.