Advances in capillary-based gaseous UV imaging detectors

We studied gain and position resolution of gaseous UV-photon detectors combining single- and cascaded- glass capillary-plate multipliers and CsI photocathodes. Two modes of operation were investigated: a conventional one, where the main amplification occurs within capillary holes and a parallel-plate amplification mode, where the main amplification occurs between the capillary plate and the readout anode. Results of these studies demonstrate that in the parallel-plate amplification mode one can reach both high gains (>105) and good position resolutions (∼100 μm) even with a single-element multiplier. This offers a compact amplification structure, which can be used in many applications.