X-ray to visible image converter with a cathode emission layer having non- uniform density profile structure

摘要

High quantum efficiency (≧5%) ultrafast (≦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 (≧10 lp/mm) and high gain (≧10.sup.4). The thickness of this panel shaped disc X-ray intensifier can be less than 1 cm. A portable real time projection X-ray imagescope which employs this new type X-ray intensifier and other devices (small x-ray tube, small built-in high voltage power supply) can be widely used for medical, industrial and security applications.