Dual-cathode Csl covered microstrip plate as VUV high efficiency photosensor

A gas proportional scintillation counter having as photosensor a dual-cathode microstrip plate covered with a CsI film is described. This dual-cathode new technique has the advantage of increasing the VUV sensitive area of the microstrip plate. A detailed description of the technique is presented together with a discussion of the performance. The results obtained for a xenon filled gas proportional scintillation counter show an improvement of the energy resolution for 5.9 keV X-rays from 12.5%, for a single cathode device, to 11.1% for the dual-cathode device.