Abstract: A direct conversion X-ray photo-electron cathode has specially designed secondary electron emission layers which provides high efficiency, low noise, high speed and broad band X-ray photon detection. The X-ray photocathode is integrated with a micro channel plate and an output phosphor display screen to form a panel type X-ray intensifier. The X-ray intensifier is combined with a micro-focus X-ray source to provide projection type X-ray microscope for use in X-ray microscopic diagnostic applications.

Abstract: High quantum efficiency (.gtoreq.5%) ultrafast (.ltoreq.100 picosecond) and broad band (30 KeV to 80 KeV for medical application) X-ray photo-electron cathode, high gain X-ray real time image intensifier and portable low intensity real time projection type X-ray imagescope use new vacuum photo-electron devices. A new type X-ray photo-electron cathode has a specially designed alkali halide electron emission layer that makes possible high quantum efficiency, high speed and broad band X-ray photon detection. An X-ray photo-electron cathode followed by a direct coupled micro channel plate and an output phosphor display screen form a new type panel shaped direct view X-ray intensifier tube which can have both high spatial resolution (.gtoreq.10 lp/mm) and high gain (.gtoreq.10.sup.4). The thickness of this panel shaped disc X-ray intensifier can be less than 1 cm.