Fast-neutron detectors for nuclear physics experiments

Fast-neutron detectors are used in a wide range of nuclear physics experiments including studies of elastic and inelastic neutron scattering, charge-exchange reactions, photonuclear reactions, neutron-induced fission, and, especially recently, reactions of radioactive nuclei. Although many of the detectors being developed now are based on technologies that are several decades old, new physics is now accessible due to the advent of advanced accelerators, and these facilities present challenging opportunities for detecting fast neutrons. The choice of detectors, their appropriateness for particular measurements and how they are integrated into experiments will be discussed. Detector arrays are of particular importance these days to study angular distributions or simply to increase the solid angle coverage to increase the data rate. Modeling the response of the detectors has become much more important in order to understand better their response and to calculate effects of neutron scattering in the experimental area, including detector-to-detector scattering. Data acquisition through waveform digitizers is now common and leads to more information from each event as well as significant reductions in dead time and in the complexity of the electronics. At the same time, analyzing waveforms in real time presents challenges in terms of handling large amounts of information. Examples of significant improvements in the utilization of neutron detectors in physics experiments, in the characterization of the detector response, and in signal processing will be presented.