GB443777A - Electron discharge amplifiers - Google Patents

Abstract

443,777. Discharge apparatus. McGEE, J. D., 9, King's Avenue, Ealing, London. July 5, 1934, No. 19823. [Class 39 (i)] In an amplifier operating by the production of secondary electrons from a target due to the impact of primary electrons thereon, the secondary electrons following a path mainly clear of that of the primary electrons and falling upon a further electrode at a higher positive potential, concentrating means serving to increase the number of incident electrons are provided between an electron source and the target, and between the target and the further electrode. In one form, a zigzag glass envelope 1 contains an indirectly-heated cathode 2, an output electrode in the form of a Faraday cage 3, a plurality of targets A1, A2, A3, A4 and a plurality of screens 4, 5, 6, 7 connected either to the targets, as shown, or to intermediate potentials. The targets and the electrode 3 are maintained at successively increasing potentials by a potential divider 9. A series of concentrating coils M, separated by magnetic screens 10, surrounds the screens 4, 5, 6, 7. The ends of the screens 4, 5, 6, 7 may be furnished with grids G, or separate grids may be inserted and a control electrode 11 may by employed. The targets may consist of caesium or other alkali metal on silver oxide. In a modification a simple tube shaped envelope contains a photo-electric cathode, and cylindrical electrodes coaxial with the screens 4 accelerate and concentrate the beam. The coils M may then be dispensed with.