Determination of <sup>238</sup> U(n, <i>γ</i> ) and <sup>238</sup> U(n, f) reactions cross-section in the neutron emission spectrum of <sup>241</sup> Am-Be source
M. Tohamy, Elsayed K. Elmaghraby, M.N.H. Comsan
Abstract
Abstract The neutron radiative capture and neutron fission cross-sections were measured over the neutron emission spectrum of an 241 Am-Be source with an effective energy range between 1 MeV and 11 MeV using the activation method. In foils were used as a neutron flux monitor based on 115 In(n, n′) 115m In reaction. The sample was a Cd-covered natural UO 2 pellet. Evaluations of the yield and reaction data in the energy range from 0.1 MeV to 11 MeV had been done to validate the integral experimental results. The neutron capture cross-section, using 239 Np decay, was 32.9 ± 0.9 stat. mb. The fission cross-section was probed using gamma lines from 143 Ce, 133 I, 105 Ru, 134 I, 91 Sr, 135 I, and 92 Sr. The weighted average value of the fission cross-section was 570 ± 24 mb. 143 Ce, 133 I, 135 I, and 92 Sr had the highest merit among fission products for the validation, use upon application of long-lived Am-Be neutrons in quantification for nuclear safeguard and security applications.