Fluence measurement of monoenergetic neutrons from D(d,n) and T(d,n) reactions at the KRISS

Abstract

A Cockcroft–Walton accelerator from High Voltage Engineering Europa BV was installed at the Korea Research Institute of Standards and Science in June 2022 to generate monoenergetic neutron fields. In this study, the fluences of monoenergetic neutron fields with energy peaks at 2.5, 2.8, and 3.2 MeV from the D(d,n) reaction and at 14.8 MeV from the T(d,n) reaction were measured. To measure neutron fluence, Bonner spheres with diameters of 17.78, 20.32, and 25.40 cm were placed at a distance of 1.50 m from the target. Additionally, a small size long counter was used separately as a neutron reference detector to monitor the stability of neutron production rate. For a deuteron beam current of 1 $\mu$A, the neutron fluences of monoenergetic neutron fields with energy peak at 2.5, 2.8, 3.2, and 14.8 MeV were determined to be 0.71 ± 0.03, 1.10 ± 0.04, 13.9 ± 0.5, and 258.0 ± 8.1 cm${}^{-2}$s${}^{-1}\mu$A⁻¹, respectively.