GB638521A - Improvements in or relating to electron multipliers - Google Patents

Abstract

638,521. Electron multipliers. ELECTRIC & MUSICAL INDUSTRIES, Ltd. July 10, 1947, No. 18229. [Class 39 (i)] An electron multiplier comprises a cathode 1, Fig. 1, which emits electrons from opposite sides thereof, a pair of secondary emissive electrodes 4 for multiplying the two electron streams, a single secondary emissive electrode 5 for further multiplying both secondary streams and a final collector electrode 6. Control grid 2 and accelerating grid 3 are provided, electrodes 4 are of plane plate form, electrode 5 is a V-shaped plate and anode 6 is a V-shaped grid. A circular shielding electrode 7 surrounds the other electrodes. In another form, Fig. 2, there are four multiplying stages, the first and third consisting of L-shaped electrodes 8, 10, the second of a plane electrode 9 and the fourth of a V-shaped electrode 11. A V-shaped grid 12 again acts as a final collector. The shield 13 is elongated as shown. There may be more than four multiplying stages. The Provisional Specification describes in addition in general terms a form similar to that of Fig. 2 and suggests that only three multiplying stages may be used.