2-D Scintillation Position-Sensitive Neutron Detector

Abstract

A new 2-dimensional scintillation position-sensitive neutron detector (PSND) with an active area of 155times155 mm2 was developed for use on the single crystal diffractometer at the intense pulsed neutron source at Argonne National Laboratory. The detector is based on the well-proven Anger camera technique and uses a 6Li glass scintillator as the neutron converter. This PSND incorporates a 6times6 PMT array with 29.6 mm pitch and optimized optics to achieve an average spatial resolution of 1.75 mm full width at half maximum. The detector read-out has separate electronics for each PMT and the neutron position is calculated by a microprocessor during acquisition. A newly developed position extraction algorithm makes use of an analytical calculation to determine the event position. This new method improves the linearity of the calculated position, provides a slight improvement in resolution, and in principle allows for the correct determination of position to the edge of the scintillator. The design of the detector enclosure allows multiple detectors to be tiled with minimal dead space between them. In addition, the design incorporates a means of attaching external shielding plates that minimizes the shielding surface area required