GB830601A - Improvements relating to electron multipliers - Google Patents

Abstract

830,601. Electron multipliers. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. May 25, 1956 [April 27, 1955], No. 12179/55. Class 39(1). In an electron multiplier comprising a cathode, an anode or a plurality of dynodes arranged therebetween, the operative surfaces of these electrodes are located on a line or face laterally across this line alternately in opposite directions, Means are provided for producing parallel magnetic and electric fields along this line, the electrons being connected to suitable potentials to obtain a uniform electric field. As shown the electrodes are flat plates and electrodes from photo-emissive cathode C follow helical paths between each of the dynodes D1-D5 to the collector anode A, the transit time spread being small since electrons which leave an electrode together arrive at the next electrode at the same time. In a modified arrangement the fields extend along a curved path and the electrode surfaces are slightly curved to conform to this path. The electric field is terminated by electrodes E, E 2 and the magnetic field is produced by solenoid For a permanent magnet. According to the Provisional Specification the dynodes may comprise screens having short tubular apertures distributed over their area.