GB456991A - Improvements in or relating to electron discharge devices - Google Patents

Abstract

456,991. Electron multipliers; circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, London, and GILL, E. W. B., Merton College, Oxford. May 24, 1935, No. 15167. [Classes 39 (i) and 40 (v)] A multiplier comprises a source of primary electrons, two opposed plate-like secondary emitting electrodes and an output electrode, and means are provided for applying an alternating potential across the plate-like electrodes having a half-period equal to the time of flight of electrons between the two plates, and further means for applying a magnetic field having a component perpendicular to the electric field and inclined so that electrons travelling from one plate to the other move also towards the output electrode. As shown, the plates 8, 9 which are secondary emissive are connected across a parallel tuned circuit Vsin pt to the centre point of which is connected the output electrode through an output impedance and a source of positive potential. The angle of inclination of the magnetic field may be variable to vary the number of stages of amplification. The primary electrons may be photo-electrons. The Specification describes but does not claim a device in which one of the plates is not secondary emitting and has maintained upon it a steady positive potential and an alternating potential, the arrangement being such that electrons travel in curved paths, returning to the secondary emissive plate at another point, and devices having a number of coplanar secondary emissive electrodes opposite a single accelerating electrode.