GB460397A - Improvements in or relating to discharge tubes using electrons and/or positive ions - Google Patents

Abstract

460,397. Discharge apparatus. ROGOWSKI, W., and MALSCH, F. April 23, 1935, Nos. 9882/36 (divided out of 460,288) and 12279/35. Convention dates, April 19, 1934 and Jan. 7, 1935. [Class 39 (i)] To reduce the voltage and the gas pressure required in cathode-ray tubes of the cold-cathode type, an auxiliary gas discharge is used to produce an electron beam which is then acceleratedand utilized as the main beam. A lateral gasdischarge between an auxiliary anode 1, Fig. 2, and auxiliary cathode 2 produces positive ions which pass through holes in the cathode 2 and are accelerated in curved tracks to strike the main cathode 3. Electrons thus liberated at the cathode 3 are accelerated through aperture 4 to form the main beam in the space 5. In a modification, ion beams from a gas-discharge behind the cathode are reversed and concentrated on to the cathode by a counter-field as described in Specification 460,288. In another modification, Fig. 3, ions from gas-discharges between electrodes 6 and 7 and between electrodes 8 and 7 flow in curved paths as shown to the cathode 6 of the main electron beam. The formation of ions is favoured by long paths followed by electrons of high ionizing power arising from the gas discharge. The emissive surface of the cathode 6 is in or near the plane of the end of the anode tube 7<1>. A control electrode biassed positively or negatively relatively to the electrode 7 may be mounted near this electrode. In other modifications, electrons from the auxiliary discharge enter the main discharge space at low speeds or are retarded in this main space to low speeds to produce ionization which may be increased by lengthening the paths of the electrons by magnetic or static or high-frequency fields. In one arrangement, Fig. 7, a gas discharge is formed between cathodes 35, 36 and an anode 37. It is stated that electrons move to-and-fro between the cathodes and ionic beams, which are used to produce electron beams, may emerge from one or more apertures 43. As shown, the anode 37 is slit and co-operates with an electrode 41 to produce an electron lens effect collecting electrons towards the axis, a control grid 47 is provided, and electrons near the aperture 43 are accelerated by an electrode 45 to form the main electron beam. In all arrangements, the main and auxiliary cathodes may be made highly emissive by using barium oxide. The Specification as open to inspection under Sect. 91 comprises also the use of silite as cathode material and refers to recording electric oscillations by a beam of ions. This subject-matter does not appear in the Specification as accepted.