Characterization of the neutron flux of a 4.3 Ci Am-Be irradiation site using the cadmium ratio k0 method

Abstract

In order to utilize the capabilities of the neutron activation analysis (NAA) method, a specialized irradiation unit was installed and operated at Damghan University with a 4.3 Ci Am-Be source. In this study, for the mentioned unit, using the cadmium ratio technique from k0 standardization methods, the neutron flux parameters were determined. Gold (197Au) and Indium (115In) were used as monitors for the irradiations, and their activities were measured with a NaI detector. The obtained values for shape factor of the epithermal neutron spectrum α in paraffin and water moderators are α = 0.0181 ± 0.0050 and α = 0.0182 ± 0.0050, respectively. The thermal to epithermal flux ratio values show that the heating rate for fast neutrons in paraffin and water moderators reached 99.1 % and 98.7 %, respectively. The measured values and their precision indicate that both moderators are suitable for use in the current configuration.