A numerical approach to calculate the full-energy peak efficiency of HPGe well-type detectors using the effective solid angle ratio

Abstract

In the field of gamma-ray spectroscopy with HPGe detectors, applied to measurements of activity when the sample to be measured is small and has low radioactivity, the well-type HPGe detectors are widely used. To determine the sample activity, the full-energy peak efficiency is needed. In this work, the efficiency transfer method (ET) in an integral form is proposed to calculate the full-energy peak efficiency and to correct the coincidence summing effect for the HPGe well-type detector. This approach is based on the calculation of the effective solid angles ratio for a well-type detector with a cylindrical source inside and an axial point source outside the detector cavity, taking into account the attenuation of the gamma-rays. The calculated values of the full-energy peak efficiency are found to be in a good agreement with the measured experimental data obtained by using a mixed radionuclide gamma-ray source containing 60Co and 88Y.

Calculation of NaI(Tl) detector full-energy peak efficiency using the efficiency transfer method for small radioactive cylindrical sources

“…The dis crep an cies be tween the cal cu lated and the mea sured ef fi cien cies, given by eq. (38), where e cal and e meas are the cal cu lated and ex per imen tally mea sured ef fi cien cies, re spec tively, are listed in tab. 4 This pa per pres ents a sim ple an a lyt i cal method to eval u ate the full-en ergy peak ef fi ciency cov er ing a wide en ergy range while, us ing iso tro pic ax ial ra dioac tive point sources, and ax ial ra dio ac tive cy lin dri cal sources.…”

“…The ef fi ciency trans fer prin ci ple, as es ti mated in [38], was ap plied to es tab lish the ef fi ciency cal i bra tion curves of the cy lin dri cal de tec tors based on the fol lowing [39,40]. The ef fec tive solid an gle for the iso tro pic co ax ial ra dio ac tive point source W eff(point) can be cal cu lated by as sum ing that, there are two main cases to be con sidered, as in di cated in fig.…”

Calibration of the Absolute Efficiency of Well-Type NaI(Tl) Scintillation Detector in 0.121–1.408 MeV Energy Range

“…Most of the authors report agreement with experimentally obtained efficiency values within 10%. One useful way to stun these complications is the use of the straightforward direct mathematical method [4][5][6][7][8][9][10][11][12][13][14][15][16][17] and the experimental measurements. For the polar ( ) and azimuthal ( ) angles, the azimuthal angle, , earns the values from 0 to 2 , while the polar angle, ( ), earns four different values built on the source-to-detector configuration.…”

Using Mathematical Procedure to Compute the Attenuation Coefficient in Spectrometry Fields

“…Based on the direct mathematical method [10][11][12][13][14][15][16][17], a new theoretical approach was introduced to determine the detector ef iciency by the use of isotropic radiating axialpoint sources located at different heights from the cylindrical detector upper surface. This method depends on the accurate analytical calculation of the average path length covered by the photon inside the detector active volume and the effective solid angle Ω eff .…”