Magnetrons
AssigneeEnglish Electric Valve Company Limited
InventorAlan H. Pickering
Life of this patent
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Abstract
A magnetron consists of a cathode structure mounted within an anode cavity arrangement. In order to prolong the operational life of the cathode structure electron emissive material is located within recesses formed in the outer surface of a cylindrical support. As the electron emissive material erodes away during operation of the magnetron its surface area remains substantially unreduced.
Claims13
A magnetron including a cathode in which a cylindrical support of good electrical conductivity material carries electron emissive material located in recesses formed in the outer cylindrical surface to provide an electron emissive surface area of a predetermined area having interruptions formed by walls of the exposed outer, cylindrical surface, the recesses having substantially constant cross sectional area in the direction of their depth so that as the volume of electron emissive material decreases during operation of the magnetron, said electron emissive surface area remains substantially unreduced.
A magnetron including a cathode in which a cylindrical support of good electrical conductivity material carries electron emissive material located in recesses formed in the outer cylindrical surface, the lateral dimensions of each recess in at least one given direction being small compared with the overall dimension of the cathode in the same direction whereby a plurality of areas of electron emissive material which are separated by intervening raised portions of said cylindrical support are positioned along said direction, and the area of the outer cylindrical surface which is occupied by said electron emissive material is large as compared to the rest of said outer cylindrical surface, and wherein the recesses have substantially constant cross sectional areas in the direction of their depth so that as the volume of electron emissive material decreases during operation of the magnetron, the electron emissive surface area remains substantially unreduced.
Dependencies are inferred from the claim text.