Author(s)

Raymond Limen Njinga^1*, Sunday Adesunloye Jonah²

¹Department of Physics, Ibrahim Badamasi Babangida University, Lapai, Nigeria.
²Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria.

Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. The gamma-ray spectrometer laboratory in Centre for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria is accredited to perform measurements of radioactive content of samples collected from the environment, food chain or industrial products with the aid of a high resolution HPGe detector. For accurate gamma-ray spectrometry, certain measurements were considered; the efficiency of the detector was performed experimentally against energies within the range of 59.50 keV (²⁴¹Am) to 2204.50 keV (²²⁶Ra) for the respective geometries of 1 - 6 cm. The sustained solid angle relations with respect to the inverse square of sample geometries from 1 - 6 cm were evaluated. Another main point of this work was focused on the efficiency at geometry of 5 cm with respect to the three selected energies: 661.60 keV (¹³⁷Cs), 1173.2 keV (⁶⁰Co) and 1332 keV (⁶⁰Co) for the main axis, ten degree off main axis, forty five degree off main axis and ninety degree off the detector main axis. In order to verify optimum geometries in our laboratory for both short lived and long lived radionuclides analyses, the evaluation of efficiencies for the respective energies: 1173.2 keV (⁶⁰Co), 1332.5 keV (⁶⁰Co), 1764 keV (²²⁶Ra) and 2294 keV (²²⁶Ra) were plotted against geometries of 1 to 6 cm from the detector end cap along the main axis.

Gamma-Ray Spectrometry, Solid Angle, Efficiency, Radioactive Measurements

Njinga, R. and Jonah, S. (2015) Calibration of the High Purity Germanium Gamma-Ray Spectrometer in CERT, ABU Zaria, Nigeria. Modern Instrumentation, 4, 11-17. doi: 10.4236/mi.2015.42002.