Gamma – Ray Spectroscopy: Effect of Strength and Distance on the Performance of a Detector

Abstract

Gamma-ray spectroscopy of gamma sources were studied using High–Purity Germanium (HPGe) semiconductor detector in this experiment. The spectra produced by ¹³⁷Cs, ⁶⁰Co, ¹⁵²Eu and unknown sources were used in evaluating the performance of the detector as regarding its efficiency, energy resolution, and ability to analyse complex spectra as well as characteristics of the source spectra. The efficiencies on two limits of energy photon was determined to be (0.20±0.00)% at 662keV to (0.11±0.01)% at 1332keV for Absolute Peak Efficiency (εₐₚ), (29.3 ±0.00)% at 662keV to (15.9 ±0.01)% at 1332keV for Intrinsic Peak Efficiency (εᵢₚ), and (0.09±6E⁻⁵)% at 662keV to (0.14 ±3E⁻⁴)% at 1332keV for Absolute Total Efficiency which were as expected. The linearity energy response ratio of 1.5% at 662keV and 0.2% at 1332keV were determined between MCA and eye inspection. Energy resolution of the detector under study was (0.2±0.1)% at range of 662 to 1332keV which was quite good when compared to standard data with gradient of –(0.6±0.8) when a graph of LogE versus LogR was plotted making it possible to analyze complex spectra from the unknown given source with clarity which is the proof the hallmark of Ge detector that gave it an edge over other detectors used for gamma spectroscopy.