Compendium on Monte Carlo simulation of photoneutrons in the Giant Dipole Resonance energy range; The First five elements

Garnaud, L.*; Ogawa, Tatsuhiko   ; 7 of others*

Photoneutrons, produced by photonuclear reactions, appear in diverse applications using high-energy gamma sources, electron accelerators, or nuclear reactors. Monte Carlo particle-transport codes typically simulate their emission, characterize their fields, and evaluate their impact on nuclear systems. This work aims to compile a compendium on photoneutron simulation using MCNP6, PHITS, and TRIPOLI-4. Each code runs with both ENDF/B-VIII.0 and JENDL-5 nuclear data libraries. We investigate photoneutron fields from 50 naturally isotopic elements, ranging from reaction energy threshold up to 30 MeV (the Giant Dipole Resonance regime). These fields are characterized by photoneutron current, energy spectrum, and angular distribution. This paper details results for the initial five elements: deuterium, beryllium, carbon, nitrogen, and oxygen, ordered by increasing atomic number. This compendium will serve as a valuable resource for users to understand code capabilities and limitations, for developers to improve neutron-emitting photonuclear reaction sampling, and for all photoneutron researchers, including nuclear data evaluators and experimental physicists.