GB364006A - Improvements in and relating to photo-electric apparatus - Google Patents

Abstract

364,006. Photo-electric cells. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Bainbridge, K. T. ; 823, Riverside Drive, New York, U.S.A.) Aug. 26, 1930, No. 25456. Convention date, Aug. 28, 1929. [Class 39 (i).] A mesh anode 4 is disposed between a lightsensitive primary cathode 3 and a secondary cathode 5 from which electrons are released by electron, from the cathode 3 impinging thereon, the cathodes being so disposed (e.g. angularly disposed) that light impinging on the cathode 3 is subjected to multiple reflec. tion. In a modification; the electrodes are concentrically arranged, a helical grid-like anode being disposed between a semicylindrical primary cathode and a cylindrical secondary cathode having a diameter less than that of the primary cathode. The secondary cathode may be light-sensitive, or may be coated with barium or with barium oxide and may have a highly reflecting surface. A nickel or copper cathode is silver-plated by electrolysis, chemical deposition, or electrical sputtering as described in Specification 190,218, [Class 39 (i), Electric lamps, Arc &c.], and is subsequently oxidized by a discharge in oxygen. Caesium is introduced-by distillation from a side tube or by heating a pellet by means of highfrequency currents ; excess caesium is removed by distillation or by means of a pump. The anode is formed of nickel or molybdenum to prevent caesium sticking thereon. The potential between the electrodes 3, 4 may be ten times that between the electrodes 4, 5. Specification 303,476, [Class 39 (i), Electric lamps, Arc &c.], is referred to.