Image intensifier tube having an internal alkali baffle

摘要

An image intensifier tube includes a substantially cylindrical envelope having a photoemissive cathode at one end and a phosphor screen at the other end. A tubulation extends through the envelope wall for introducing a constituent of the cathode into the envelope. A baffle ring comprising an insulative material is located within the tube adjacent to the tubulation. The baffle ring forms an interior annular chamber with the cylindrical envelope. An annular passage is formed between the baffle ring and an inwardly-extending portion of the envelope.