Position sensitivity within a bar of stilbene coupled to silicon photomultipliers
2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016
A 6-mm by 6-mm by 50-mm bar of stilbene was coupled on both ends to silicon photomultipliers (SiPMs) to assess the detector's position sensitivity to interactions throughout the bar. A Na-22 gamma ray source was collimated with a pair of lead bricks to produce a source beam that was used to irradiate five positions along the length of the bar. A logarithmic relationship between the ratio of the pulse heights obtained from the two SiPMs and the position of the collimated source was established. The standard deviation of the distribution of ratios from each measurement was propagated through the functional form to determine position resolution. The position resolution along the length of the bar was determined to have an average value of 4.9 mm.