Miniature imaging photon detectors. II. Devices with transparent photocathodes

Abstract

For pt.I, see ibid., vol.13, no.12 (1980). A two-dimensional imaging photon detector has been developed using a proximity-focused transparent photocathode (S25), three microchannel plates in a 'Z' configuration and a proximity-focused 'linear' resistive anode. The device shows a detected quantum efficiency of about 15% at 500 nm, 5% at 630 nm and 1% at 800 nm and a stable performance in extended operation which should correspond to many years of continuous use in practical applications in astronomy and geophysics. With the 18 mm photocathode and microchannel plates presently used, about 4*4⁴ pixels can be obtained, corresponding to a FWHM resolution of 100 mu m at an electron gain of 10⁷.