GB471800A - Improvements in or relating to electron discharge apparatus - Google Patents

Abstract

471,800. Electron multipliers. WEISS, G. Jan. 8, 1936, Nos. 633, 634, and 636. Convention dates, Jan. 8, 1935, Feb. 1, 1935, and May 24, 1935. [Class 39 (i)] A multiplier comprises a cathode, a collecting anode, and a plurality of secondary emission electrodes which are pervious to an electron stream and are arranged in the path of the stream from cathode to anode. In one form, a number of thin metal grid or mesh electrodes, e.g. of silver, coated with caesium or other alkaline metal, are disposed between a cathode which may be photo-electric or thermionic, and a collecting electrode. In a modification, Fig. 2, the plate electrode 3 is secondary emitting and the electrode 1 is the collector. A number of parallel annular or rectangular mesh electrodes may be arranged above and at the side or centrally with respect to a photoelectric cathode and may be heated to increase their emission. A solenoid may concentrate the beam, and electrostatic or magnetic focusing means may project electron images from the cathode and secondary emitting electrodes onto succeeding electrodes. In another form, Fig. 8, a photo-electric cathode 2 may be arranged in a bottle-shaped tube 7, in the neck of which are arranged the secondary emitting electrodes 1, 101, 111, 121 and the collector 3. The Specification as open to inspection under Sect. 91 describes also the arrangement shown in Fig. 7 (Cancelled), wherein electron beams are accelerated by grids 4, 104, 114, 124 and impinge upon secondary emission electrodes 5, 105, 115, 125 and a collector electrode 3, and states that the secondary-emitting electrodes may be pervious foils. The Specification includes also the subject-matter of Specification 468,665. This does not appear in the Specification as accepted.