New Measurements of Photoneutron Spectra investigating specific signatures of Carbon, Nitrogen, and Oxygen

Abstract

We report new measurements on photoneutron spectra from graphite, glucose, and melamine, revealing distinct signatures corresponding to carbon, oxygen, and nitrogen individual elements. Using a 23-MV electron linear accelerator (LINAC) and EJ-309 liquid scintillators with advanced pulse shape discrimination and pile-up rejection algorithms, we successfully detected fast neutrons from photo-nuclear (γ,Xn) reactions within an intense pulsed photon field. Energy deposition from fast neutrons was unfolded using two well-known independent algorithms ML-EM and GRAVEL. Our findings indicate discrepancies between the experimental results and Monte-Carlo simulations performed with the widely-used code MCNP6, highlighting the need for new data in order to improve the models used for the simulation of photoneutron production. These results have significant implications for various nuclear physics applications, including electron accelerator facilities decommissioning, illicit material detection for homeland security, and global radiotherapy patient dosimetry including neutron dose.