Monte Carlo simulation study on simultaneous detection of neutrons and gamma-rays with a GdI3:Ce scintillator detector

Abstract

Neutron detection using gadolinium (Gd) and its prompt gamma-rays is vital because of the high cross-section of Gd on thermal neutrons, thereby leading to significant interest in neutron detection with Gd-converted or Gd-loaded detector. However, simultaneous detection of neutron and gamma-rays with a Gd-loaded scintillator has been given less attention. In this study, we explored the feasibility of the GdI3:Ce detector for simultaneous detection with Monte Carlo N-Particle transport extended simulation. Furthermore, we examined the physical properties of Gd for application in the radiation field mixed with neutron and gamma-rays. Similarly, we simulated the geometry of the GdI3:Ce scintillator and its spectra obtained under various conditions. The results showed that GdI3:Ce with a thickness of 1[Formula: see text]cm is enough to absorb 90[Formula: see text] of photons with energy under 81[Formula: see text]keV. A shorter source-to-detector distance and larger detector size were superior to detecting prompt gamma-rays emitted from neutron capture, not only the gamma-rays from isomeric transition (named as general gamma-ray in this paper). Ultimately, spectra taken with the Gd3:Ce scintillator under the radiation field mixed with neutrons and gamma-ray showed gamma-ray peaks from both radio-isotopes and Gd[Formula: see text]Gd reaction, indicating the feasibility of the application of simultaneous detection.