developments in gamma spectrometry alexandria university, faculty of engineering nuclear engineering...
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Developments in gamma spectrometryDevelopments in gamma spectrometry
Alexandria University, Faculty of Engineering Nuclear Engineering Department
JINR, Frank Laboratory of Neutron Physics
Department of Neutron Activation Analysis
Ashraf KAKA
Supervisor: Dr. Marina FRONTASYEVA
General considerations in General considerations in gamma-ray spectrometrygamma-ray spectrometry
11 Photoelectric absorptionPhotoelectric absorption
22 Compton scatteringCompton scattering
33 Pair productionPair production
Photoelectric absorptionPhotoelectric absorption
Compton ScatteringCompton Scattering
Pair ProductionPair Production
511 eV
Probability ofProbability of
interaction of photon interaction of photon
with matterwith matter
Gamma-ray spectrometer systemGamma-ray spectrometer system
PreamplifierPreamplifier
The pulses produced in the detector are The pulses produced in the detector are
very small and so the charge sensitive very small and so the charge sensitive
preamplifier, usually a field-effect transistor preamplifier, usually a field-effect transistor
(FET), is mounted as close to the detector (FET), is mounted as close to the detector
as possibleas possible
AmplifierAmplifier
The amplifier increases the size of the The amplifier increases the size of the small signal from the output of the small signal from the output of the preamplifier to a pulse of amplitude up to preamplifier to a pulse of amplitude up to about 10 V, dependent on the gain settingabout 10 V, dependent on the gain setting
The second purpose of the amplifier is to The second purpose of the amplifier is to improve the signal to noise ratio of the improve the signal to noise ratio of the given pulsesgiven pulses
Photo multiplier tubePhoto multiplier tube (PMTS)(PMTS)
ConclusionConclusion
The quality of gamma-spectrometers can The quality of gamma-spectrometers can be improved by using of a small size PMTbe improved by using of a small size PMT
to increase the efficiency of the detector to increase the efficiency of the detector and to minimize its sizeand to minimize its size
Thank you for attentionThank you for attention!!