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

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 Phi(th) = 1.46 x 10(4) n cm(-2) s(-1) +/- 0.01 x 10(2), epithermal neutron flux Phi(epi) = 7.23 x 10(2) n cm(-2) s(-1) +/- 0.001, fast neutron flux Phi(f) = 1.26 x 10(2) n cm(-2) s(-1) +/- 0.020, thermal-toepithermal flux ratio f = 20.5 +/- 0.36 and epithermal neutron shaping factor alpha = -0.239 +/- 0.003 were found for irradiation Site-1: while the thermal neutron flux Phi(th) = 4.45 x 10(3) n cm(-2) s(-1) 0.06, the epithermal neutron Phi(epi) = 1.50 x 10(2) n cm(-2) s(1) 0.003, the fast neutron flux Phi(f) = 1.17 x 10 n cm(-2) s(-1) +/- 0.011, thermal-to-epithermal flux ratio f = 29.6 +/- 0.94, and epithermal neutron shaping factor alpha = 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. (C) 2011 Elsevier Ltd. All rights reserved.