Accounting for incomplete charge collection in Monte Carlo simulations of the efficiency of well-type Ge-detectors

New Analytical Formulae to Calibrate Well-type Scintillation Detectors Efficiency

“…The comparison between the calculated values of efficiencies and experimental ones provided in these papers shows that the error is very small. This method proves its accuracy and success for many detector geometries; like: coaxial detectors [1][2][3][4], parallelepiped detectors [5] and borehole detectors [12]; and types like: semiconductors [4][5][6][7] and scintillators [1][2][3] Besides, the direct mathematical method is built on simple mathematical approach and it does not need long computer programs nor previous experimental calculation of the efficiency of standard source like other Monte Carlo method [13][14][15][16]. In this work we used direct mathematical method to predict the efficiency of two well type detectors, in detecting the gamma photons produced by sources placed in their well cavities, over wide range of photon energy for seven different source geometries and positions including point sources with very small dimensions and cylindrical sources.…”

A detailed investigation of HPGe detector response for improved Monte Carlo efficiency calculations

“…Work has been done by Hernandez and El-Daoushy [31] and Friedman et al [25] in order to calculate the electrical field and its variation over the crystal. They propose that regions in the detector with reduced electrical field, and correspondingly longer collection times, will have only partial charge collection and hence will not contribute to the full energy peak.…”

“…Even though the electrical field is generally considered to be fairly independent of the bias voltage above the depletion level, there is a slight increase with increasing bias voltage [40]. If the reduced sensitivity of this detector is due to effects of the electrical field in the way described by Hernandez and El-Daoushy [31] and Friedman et al [25], significantly reducing the bias voltage should affect the detection efficiency.…”

“…Furthermore, it has been suggested that a decrease in efficiency arises from the properties of the electrical field in the detector causing incomplete charge collection [25,31].…”

Mathematical method to calculate full-energy peak efficiency of detectors based on transfer technique

“…The calculation of absolute activities of natural and artificial radionuclides by gamma spectrometry requires reliable and accurate determination of the detector full-energy peak efficiency [1]. The main problem of the measurements in the well-type detector geometry is the presence of high coincidence summing effects in the case of multi-photonemitting radionuclides.…”