New approach to calculate the true-coincidence effect of HpGe detector

• Main Authors: Alnour, I. A., Wagiran, H., Ibrahim, N., Hamzah, S., Siong, W. B., Elias, M. S.
• Format: Conference or Workshop Item
• Published: American Institute of Physics Inc. 2016
• Subjects: QC Physics
• Online Access: http://eprints.utm.my/id/eprint/73456/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984559407&doi=10.1063%2f1.4940074&partnerID=40&md5=c0c5545a3be84a5c48e9345ea0fceb8a

The corrections for true-coincidence effects in HpGe detector are important, especially at low source-to-detector distances. This work established an approach to calculate the true-coincidence effects experimentally for HpGe detectors of type Canberra GC3018 and Ortec GEM25-76-XLB-C, which are in operation at neutron activation analysis lab in Malaysian Nuclear Agency (NM). The correction for true-coincidence effects was performed close to detector at distances 2 and 5 cm using 57Co, 60Co, 133Ba and 137Cs as standard point sources. The correction factors were ranged between 0.93-1.10 at 2 cm and 0.97-1.00 at 5 cm for Canberra HpGe detector; whereas for Ortec HpGe detector ranged between 0.92-1.13 and 0.95-100 at 2 and 5 cm respectively. The change in efficiency calibration curve of the detector at 2 and 5 cm after correction was found to be less than 1%. Moreover, the polynomial parameters functions were simulated through a computer program, MATLAB in order to find an accurate fit to the experimental data points.