Badawi M.S., Nafee S.S., Diab S.M., El-Khatib A.M., El-Mallah E.A.
CALCULATE THE EFFICIENCY OF GAMMA-RAY DETECTORS FOR INVERTED WELL BEAKER SOURCES USING AN ANALYTICAL EFFICIENCY TRANSFER PRINCIPLE ^{[№ 9 ' 2013]}
Different sources efficiency measurements and the construction of the corresponding calibration curve are usually carried out in gamma-ray spectrometry to calculate the unknown activity for different sources in the same geometry or in order to facilitate the efficiency computation of different source geometries by the use of the efficiency transfer method. In this work, the Full Energy Peak Efficiency value (FEPE) of HPGe detector has been calculated using axial inverted well beaker sources of different dimensions by an analytical approach of effective solid angle ratio. Calculation taking into account the source self attenuation effect, this approach is based on the direct mathematical method. In the experiments gamma aqueous sources containing 152Eu radionuclide's covering the energy range from 121 to 1408 keV were used. By comparison, the theoretical and experimental full-energy peak efficiency values are in good agreement.

Krar M.E., Badawi M.S., El-Khatib A.M.
USING THE EFFICIENCY TRANSFER METHOD TO CALCULATE THE (FEPE) FOR COMBINATION OF TWO G-DETECTORS BY USING RADIOACTIVE PARALLELEPIPED SOURCES ^{[№ 9 ' 2013]}
The full energy peak efficiency (FEPE) of two g-detectors by using radioactive parallelepiped sources is computed using a new analytical approach. The approach based on the efficiency transfer method (ET), the effective solid angles and explains the effect of self– absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive parallelepiped sources containing aqueous 152Eu radionuclide which produces photons with a wide range of energies from 121 up to 1408 keV. The comparison shows a good agreement between the measured and calculated efficiencies for the detector using parallelepiped sources.

Badawi M.S., El-Khatib A.M., Elzaher M.A., Thabet A.A., Sakr A.A.
USING AN ANALYTICAL EFFICIENCY TRANSFER PRINCIPLE TO CALCULATE THE FULL ENERGY PEAK EFFICIENCY FOR GAMMA DETECTORS ^{[№ 5 ' 2013]}
In this work the Full-Energy Peak Efficiency of NaI(Tl) — scintillation detectors (5.08x5.08 cm² and 7.62x7.62 cm²) values have been calculated for axial cylindrical sources of different dimensions larger than the detectors using an analytical approach of effective solid angle calculation. This approach is based on the ratio of the source-detector solid angle with taken the source self absorption effect in to account. The detector efficiency for various geometrical conditions is derived from the known efficiency for reference source-detector geometry. The present method shows a great possibilities to calibrate the detectors through the determination of the full-energy peak efficiency curve even in those case when no standard source is available and this consider as the final goal of this work.

Badawi M.S., Gouda M.M., El-Khatib A.M., Nafee S.S., El-Mallah E.A.
NEW ANALYTICAL APPROACH TO CALIBRATE CYLINDRICAL HPGE DETECTOR INCLUDING CORRECTIONS FOR SELF ATTENUATION OF LARGE CYLINDRICAL SOURCES AND ATTENUATION OF ALL DETECTOR HOUSING MATERIALS ^{[№ 5 ' 2013]}
HPGe semiconductor detectors are very useful for radioactivity measurement and to calculate the absolute activity, the full energy peak efficiency of the detector is needed. In this work, to calibrate the co-axial HPGe semiconductor detector, we introduce a new theoretical approach based on the Direct Statistical method proposed by Selim and Abbas to calculate the full-energy peak efficiency for cylindrical detectors. The present method depends on the accurate analytical calculation of the average path length covered by the photon inside the detector active volume and the geometrical solid angle, Щ, to obtain a simple formula for the efficiency. In addition, self attenuation of source matrix (with radius greater than the radius of the detector), the attenuation by the source container and the detector housing materials are also treated by calculating the average path length cross these materials. 152 Eu aqueous sources covering the energy range from 121 up to 1 408 keV were used. Remarkable agreement between the measured and the calculated efficiencies is achieved with discrepancies less than 2 %.