Focusing arrangement for electron discharge devices of electron velocity modulation tpe

摘要

579,155. Electron oscillators. STANDARD TELEPHONES & CABLES, Ltd., FREMLIN, J. H., and HALL, R. N. Aug. 2, 1940, No. 12518. [Class 39 (i)] In a velocity modulated electron oscillator such as described in Specifications 541,664 and 573,490, [Group XX], polepieces 8, 9 for the focusing magnet are arranged within the envelope ; one, 9, may act as the collector electrode, its sides being covered with a conductive layer and its face shaped or coated to suppress secondary emission. The polepiece 8 is insulated from the metal envelope 6 by a lining 10 ; this polepiece may be connected to the cathode. A permanent or electromagnet may be used. An elongated cathode 4 with focusing electrode 5 directs a long beam through the fins 2, 3 within the resonator. In a modification, the permanent magnet with polepieces 81, 9', Fig. 2, forms part of the envelope 11; this may be enclosed in a glass envelope.