GB529837A - Improvements relating to electron discharge devices employing secondary emission - Google Patents

Abstract

529,837. Electron-multipliers. KOLSfERBRANDES, Ltd., SHANNON, D. S. B., and CHATTERJEA, P. K. April 22, 1939, No. 12126. [Class 39 (i)] To obtain increased emission from the secondary emitting electrode F it is impacted by two streams of primary electrons with differing velocities one or both of the streams being modulated. Two thermionic cathodes A1, A2, Fig. 1, are surrounded by screen and control grids, and separated by a shield G and are enclosed in an electrostatic guide D ; the cathodes are at different potentials so that there are two electron streams of different velocity passing through the grid anode E. The guide D, the shield G, the control and screen grids may be in two parts; rods or flat strips may act as the screen grids. A single filamentary cathode J, Fig. 5, with a shield G may supply the two streams, the potential fall along the cathode providing the necessary velocity difference. Deflecting plates may be used to change the direction of the electrons ; a filamentary cathode A, Fig. 8, may supply two streams-obtained by use of the shield G-to impact the electrode F. In a further form two cathodes separated by shields &c. have a continuous heating filament.