Regular Article

Compendium on Monte Carlo simulation of photoneutrons in the Giant Dipole Resonance energy range

¹ Université Paris-Saclay, CEA, SERMA, 91191 Gif-sur-Yvette, France
² Université Paris-Saclay, CEA, List, 91120 Palaiseau, France
³ CEA, DAM, DIF, 91297 Arpajon, France
⁴ Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1106, Japan

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 28 August 2025
Received in final form: 13 October 2025
Accepted: 27 November 2025
Published online: 30 January 2026

Abstract

Photoneutrons–neutrons produced through photonuclear reactions–play a critical role in radiation transport scenarios involving high-energy gamma sources, electron accelerators, and nuclear reactors. Accurate modeling of photoneutron production and transport is still a challenging problem, due to limitations in photonuclear data and the sensitivity of simulations to the choice of physics models. In this study, we present a comprehensive investigation of photoneutron generation using three state-of-the-art Monte Carlo codes–MCNP6^®, PHITS, and TRIPOLI-4^®–each coupled with two major nuclear data libraries: ENDF/B-VIII.1 and JENDL-5. Photon-induced neutron production is analyzed across 49 elemental targets for incident photon energies from the photonuclear threshold up to 30 MeV, encompassing the Giant Dipole Resonance (GDR) region. Key observables–photoneutron currents, energy spectra, and angular distributions–are systematically evaluated as a function of atomic number. The resulting dataset serves as a reference benchmark for simulation validation, informs future improvements in photonuclear modeling and nuclear data, and supports broader applications in theoretical and experimental nuclear physics.