Gamma-ray gradiometry for point-source location

Abstract

A method to extract the location of a point source, from the counts obtained by two gamma-ray detectors at different distances from the source, has been developed. With two 4 litre NaI crystals at a separation of approximately 2 m from each other, only a few seconds of data are necessary to reconstruct the distance with a precision of better than about 20%, to a 600 µCi 137Cs source, up to 10 m away.