"Photocathodes." . . "Photons." . . "Ultraviolet radiation." . . "Electron bombardment." . . "Detection." . . "Microchannel plates." . . "Radiation counters." . . . "\"An investigation on specific performance details of photon counting, ultraviolet image sensors having 2-dimensional formats is reviewed. In one study, controlled experiments were performed which compare the quantum efficiencies, in pulse counting mode, of CsI photocathodes deposited on (1) the front surface of a microchannel plate (MCP), (2) a solid surface in front of an MCP, and (3) an intensified CCD image sensor (ICCD) where a CCD is directly bombarded by accelerated photoelectrons. Tests indicated that the detection efficiency of the CsI-coated MCP at 1026 A is lower by a factor of 2.5 than that of the MCP with a separate, opaque CsI photocathode, and the detection efficiency ratio increases substantially at longer wavelengths (ratio is 5 at 1216 A and 20 at 1608 A).\"--NTRS abstract."@en . . . . . "Photon-counting image sensors for the ultraviolet semi-annual report for NASA grant NSG-7618"@en . . . . . . . . . . . . . . . . . . . . . . "Image converters." . . "Quantum efficiency." . . "Photoelectrons." . .