Research and Development of a Channeled-Electron Image Intensifier

A brief description is given of the operating principle and possible electrode structures of a channeled-electron image intensifier. Details of the design and construction of the tube are described and the development of the optimum parameters in the design outlined. Investigation of the secondary emitting properties of the KCl, MgO, SbCs3, and BaF2 has led to the choice of KCl as the most practical secondary emitter for the dynodes. A method is also described in which the photocathode is processed in a separate chamber and is then transferred to the intensifier body before seal-off. A thirteen stage tube using KCl as a secondary emitter has been constructed giving an electron gain of 8×105, and with blue light gain of over 106. Resolution is in agreement with the expected theoretical resolution. A net gain of 2.1 in resolution is further obtained by dynamically scanning the tube in the plane of the image with a random amplitude and orientation. Finally, life tests are given on the stability of the electron gain and photocathode sensitivity.