Neutron energy spectrum with microstructured semiconductor neutron detectors

Microstructured semiconductor neutron detector (MSND) devices have achieved 42% intrinsic efficiency when operated as a dual-detector device. The neutron energy spectrometer has alternating layers of MSND arrays, cadmium, and high-density polyethylene (HDPE) in a linear arrangement. The detector arrays consist of 4 dual-detector devices with 1-cm² detector elements in a stacked configuration. A 2 mm thick layer of cadmium separates each detector from the following layer of HDPE. The cadmium layer prevents thermalized neutrons from backscattering into the previous detector. The 3-cm thick HDPE layers act as a moderator for the epithermal and fast neutrons, allowing them to disperse energy within the spectrometer´s volume and reach thermal energies to be detected by the MSND arrays. The resultant device is a neutron energy spectrometer with a large surface area for the incident neutron beam.