A method for the digital discrimination of neutrons and γ-rays in mixed radiation fields is described. Pulses in the time domain, arising from the interaction of photons and neutrons in a liquid scintillator, have been produced using an accepted empirical model and from experimental measurements with an americium–beryllium source. Neutrons and γ-rays have been successfully discriminated in both of these data sets in the digital domain. The digital discrimination method described in this paper is simple and exploits samples early in the life of the pulse. It is thus compatible with current embedded system technologies, offers a degree of immunity to pulse pile-up and heralds a real-time means for neutron/γ discrimination that is fundamental to many potential industrial applications.
This paper is an example of the research supporting the development of a portable digital neutron spectrometer, which was commercialized via a spin-out company (www.hybridinstruments.com), resulted in IP protected by patent (GB2422195 September 2003). This returns royalties to the academic team and also stimulated the award of a DTi R