Development of a portable Single Sphere Neutron Spectrometer.

A portable Single Sphere Neutron Spectrometer (SSNS) is designed to measure the neutron energy spectrum in the mixed radiation field. The spectrometer consists of a 30 cm diameter single polyethylene moderating sphere with 19 pieces 6Li and 1-piece 7Li glass scintillator detectors located at the orthogonal X/Y/Z axis. The output signals from each detector are processed and readout by the Silicon Photomultipliers (SiPMs) and the Application Specific Integrated Circuit (ASIC) electronic system. The neutron energy responses of portable SSNS are calibrated in the mono-energetic neutron reference fields (144 keV, 1.2 MeV, 5 MeV, 14.8 MeV) based on the 5SDH-2 tandem accelerator in China Institute of Atomic Energy, which are also simulated from 0.0253 eV to 20 MeV by Monte Carlo simulation. The performance of portable SSNS is tested at different distances in 241Am–Be neutron reference radiation field in National Institute of Metrology, China. The fluence response of SSNS is about 0.28 cm2 for 241Am–Be neutron source. • A portable Single Sphere Neutron Spectrometer (SSNS) is designed to measure the neutron energy spectrum. • The output signals from each detector are processed and readout by the SiPMs and the ASIC electronic system. • The SSNS is calibrated in monoenergetic neutron reference radiation fields. • The neutron energy responses are simulated by Monte Carlo simulation. • The performance of portable SSNS is tested in 241Am–Be neutron reference radiation field. [ABSTRACT FROM AUTHOR]