GB493296A - Improvements in or relating to electron multipliers - Google Patents

Abstract

493,296. Electron multipliers. FERNSEH AKT.-GES. April 5, 1937, No. 9616. Convention date, April 3, 1936. [Class 39 (i)] A multiplier, in which the electron stream is controlled by electrostatic and magnetic fields so as to be incident in turn upon each of a number of secondary electron emitting electrodes which are parallel to the magnetic field, comprises an accelerating electrode system and a system of secondary emitting electrodes and one of the systems lies on the surface of a cylinder and the other lies on the surface of a spiral. Secondary electrodes 3, 4, Fig. 1, lie on a spiral at the centre of which a partly cylindrical accelerating electrode 2 is arranged. Light is reflected on to the light sensitive electrode 3 by a mirror 11. A magnetic coil 15 is provided. In another form, overlapping flat secondary electrodes 3, 4, Fig. 2, are used and primary electrons are projected on to the electrode 3, through a controlling diaphragm 13 from a filamentary cathode 12. In a further form, the secondary electrodes 3, 4, Fig. 3, lie on a cylinder the axis of which is the origin of the spiral accelerating electrode 2. Light is projected on to the electrode 3 which has an extension 14 to prevent electrons from the electrode 3 flowing directly to the innermost portion of the electrode 2.