Spatial resolution of neutron-position scintillation detectors

A neutron PSD has been developed for the Intense Pulsed Neutron Source at Argonne. A pulsed source has a broad spectrum of neutron energies in which a greater fraction of the flux is in the epithermal range. Secondly there is a high instantaneous neutron flux. The detector should therefore have a high neutron detection efficiency extending to epithermal energies and a high instantaneous count rate capability. This detector is comprised of an array of photomultiplier tubes (PMTs) coupled to a thin 6Li-glass scintillator. The principle of operation is similar to that of an Anger gamma-ray camera used in nuclear medicine. The operation and performance of the detector are described. The parameters which affect the spatial resolution are examined and resolution measurements and calculations are reported. Suggestions to improve resolution are made. (U.K.)