GB644583A - Electron beam tube - Google Patents

Abstract

644,583. Thermionic distributers. STANDARD TELEPHONES & CABLES, Ltd. Jan. 24, 1947, No. 2280. Convention date, Jan. 26, 1946. [Class 40 (iii)] [Also in Group XL (a)] A thermionic distributer tube has a plurality of rows of target elements supported from the envelope at longitudinally spaced intervals thereon, each row comprising a number of target elements arranged in a circle, and means for deflecting an electron beam in a circle and varying the angle of deflection of the beam to determine the row of targets on which the beam impinges. The beam is sufficiently narrow to impinge on only one target element at a time. The target elements may comprise a number of short wires 16, Fig. 1, sealed radially through the envelope and each row may be screened from the next by an annular metallic shield 15. The beam may be given a circular deflection electrostatically and may then be further deflected by a toroidal coil 10 to impinge on the desired row of targets. The coil 10 may be fed with a stepped saw-tooth wave so that the beam impinges on each row in succession. In a modification, Fig. 4 (not shown), the lengths of the target wires are progressively increased from row to row so that the beam can be shifted from one row to the next by reducing the diameter of the scanning circle. In a further modification, Fig. 5, the target wires are bent so that their ends 30 are substantially equidistant from the centre of deflection of the beam. Specification 644,571, [Group XXXV], is referred to.