Theoretical Optimization of Neutron and Physical Characteristics of a Multiplying Pulsed Neutron Source Based on a Proton Accelerator

Abstract

The neutron source operating at the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research (JINR, Dubna, Russia), based on an IBR-2M pulsed reactor with a flux density of thermal neutrons of ~1013 n/(cm2 s) will exhaust its resource and be shut down by 2034. Optimizing this reactor to provide higher neutron flux density is practically impossible. Therefore, it is proposed to consider using a subcritical pulsed neutron source driven by a proton accelerator as a substitute for the IBR-2M. At present, nonmultiplying neutron sources based on high-current proton accelerators are mostly used around the world, for example, SNS or ESS with a beam power of 3 and 5 MW, respectively. In this paper, we present a theoretical comparative analysis of different categories of pulsed neutron sources driven by high-current proton beams, which can help to find the optimum solutions. It is shown that the subcritical one-zone booster with a tungsten target and a plutonium dioxide core can be a promising option. This type of source can provide an average thermal neutron flux density of more than 5.0 × 1014 n/(cm2 s) at a proton-beam power of 0.1–0.2 MW.