Gamma-insensitive fast neutron detector with spectral source identification potential

A neutron scintillation detector based on high-pressure 4He has been developed and tested. The detector responds to elastic scattering of unmoderated fast neutrons, preserving neutron energy, position, and timing information. Neutrons from three different sources, AmBe, 252Cf, and from the ambient background, have been measured with clearly distinct energy spectra. Exposing the detector to different levels of gamma radiation up to 1 mSv/h from a 60Co source has demonstrated that gamma exposure does not affect neutron detection performance within measurement statistics. Applications in the field of radiation portal monitoring are discussed.