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.

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 %.