Work at Imperial College on Image Intensifiers with Transmitted Secondary Electron Multiplication

The construction and properties of some magnetically focused Image intensifiers incorporating potassium chloride films as transmitted secondary electron multiplying dynodes is described. Tubes have been prepored with five dynodes which give a total electron multiplication of the order of 3000. Single electrons leaving the cathode of these tubes give rise to scintillations at the output phosphor with diameters of about 40 microns, which are bright enough to be photographed.