Performance of an Imaging Gas Scintillation Proportional Counter with Microchannelplate Read-Out

Energy and position resolution measurements have been carried out on an imaging gas scintillation proportional counter with microchannelplate read-out. Despite the degradation of the CsI photocathode due to exposure to air, an energy and position resolution of 14.8% and 1.8 mm at 5.9 keV and 5.4 keV, respectively, has been obtained. The measured values are in very good agreement with the predictions based on the measured quantum efficiency of the CsI photocathode. On the basis of this agreement one predicts that energy and position resolutions of better than 10% and 1 mm, respectively, can be achieved.