Neutron flux determination in irradiation sites of an Am-Be neutron source at NNRI

Abstract

Neutron flux measurements and flux distribution parameters for two irradiation sites of an Am-Be neutron source irradiator were measured by using gold (Au), zirconium (Zr) and aluminum (Al) foils. thermal neutron flux Φth = 1.46 × 104 n cm-2 s -1 ± 0.01 × 102, epithermal neutron flux Φepi = 7.23 × 102 n cm-2 s -1 ± 0.001, fast neutron flux Φf = 1.26 × 102 n cm-2 s-1 ± 0.020, thermal-to-epithermal flux ratio f = 20.5 ± 0.36 and epithermal neutron shaping factor α = -0.239 ± 0.003 were found for irradiation Site-1; while the thermal neutron flux Φth = 4.45 × 10 3 n cm-2 s-1 ± 0.06, the epithermal neutron Φepi = 1.50 × 102 n cm-2 s1 ± 0.003, the fast neutron flux Φf = 1.17 × 10 n cm-2 s-1 ± 0.011, thermal-to- epithermal flux ratio f = 29.6 ± 0.94, and epithermal neutron shaping factor α = 0.134 ± 0.001 were found for irradiation Site-2. It was concluded that the Am-Be neutron source can be used for neutron activation analysis (NAA). The Am-Be source can be used for neutron activation analysis thereby reducing the burden on GHARR-1 and increasing the research output of the nation. © 2011 Elsevier Ltd. All rights reserved.