Study on the energy response to neutrons for a new scintillating-fiber-array neutron detector

Abstract

The energy response of a new scintillating-fiber-array neutron detector to neutrons in the energy range 0.01 MeV ⩽E n ⩽14 MeV was modeled by combining a simplified Monte Carlo model and the MCNP 4b code. In order to test the model and get the absolute sensitivity of the detector to neutrons, one experiment was carried out for 2.5 and 14 MeV neutrons from T(p,n) 3 He and T(d,n) 4 He reactions at the Neutron Generator Laboratory at the Institute of Modern Physics, the Chinese Academy of Science. The absolute neutron fluence was obtained with a relative standard uncertainty 4.5% or 2.0% by monitoring the associated protons or 4 He particles, respectively. Another experiment was carried out for 0.5, 1.0, 1.5, 2.0, 2.5 MeV neutrons from T(p,n) 3 He reaction, and for 3.28, 3.50, 4.83, 5.74 MeV neutrons from D(d,n) 3 He reaction on the Model 5SDH-2 accelerator at China Institute of Atomic Energy. The absolute neutron fluence was obtained with a relative standard uncertainty 5.0% by using a calibrated long counter. The results show that the calculated absolute sensitivity from the model agrees with the experimental data considering the expanded relative uncertainty 15% in the experiments.