Polyethylene moderator optimized for increasing thermal neutron flux in the NASBEE accelerator-based neutron field

Abstract

Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) at National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (NIRS-QST) achieved thermal neutron flux of a therapeutic intensity of (1.75 ± 0.13) × 109 cm−2 s−1 by optimizing polyethylene (PE) moderator in the beam port. The dose contamination of gamma rays was 2.37 × 10−12 Gy cm2 (the absorbed dose of 14.9 Gy h−1). The improved thermal neutron field at the NASBEE facility will be useful in the research and development for boron neutron capture therapy (BNCT).