Abstract:
A filament assembly for use in an x-ray emitting device or other filament-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes a filament assembly for emitting a beam of electrons during tube operation. The filament assembly comprises a heat sink and a plurality of filament segments. The filament segments are configured for simultaneous emission of an electron beam for impingement on the target surface of the anode, and are electrically connected in series. Each filament segment includes first and second end portions that are thermally connected to the heat sink, and a central portion that can be configured with a modified work function for preferential electron emission.
Abstract:
A filament assembly for use in an x-ray emitting device or other filament-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes a filament assembly for emitting a beam of electrons during tube operation. The filament assembly comprises a heat sink and a plurality of filament segments. The filament segments are configured for simultaneous emission of an electron beam for impingement on the target surface of the anode, and are electrically connected in series. Each filament segment includes first and second end portions that are thermally connected to the heat sink, and a central portion that can be configured with a modified work function for preferential electron emission.
Abstract:
A directly heated cathode structure includes a porous pellet impregnated with a cathode material, a first metal member fixed to a surface of the porous pellet, a second metal member welded to the first metal member, and a filament interposed between the first and second metal members. A method for manufacturing a directly heated cathode structure includes manufacturing a porous pellet having a multiplicity of cavities, welding a first metal member to a surface of the porous pellet with a brazing layer, impregnating the cavities of the pellet with an electron radiating material, and welding a second metal member to the first metal member with a filament disposed between the first and second metal members. The useful life of the cathode structure is prolonged since thermions are not emitted through the surface of the pellet covered by the metal member.
Abstract:
A cathode-heating device comprises an emitter (1) secured on central sections (3) of at least two filament-like heating elements (4), whose peripheral sections (5) are oriented at the same sharp angle ( alpha ) to the longitudinal geometrical axis (2) of the emitter (1) and are secured by their ends to current supply buses (6). The ends of the peripheral sections (5) are located at the vertices of a polygon with two mutually perpendicular axes (8, 9) of symmetry, one of which passes through the axes of the current supply buses (6) and whose intersection point lies on the axis (2) of the emitter (1).
Abstract:
A directly heated cathode structure includes a porous pellet (500) in which cathode material is impregnated, a first metal member (510) being fixed to the lower surface of the porous pellet (500), a second metal member (520) being welded with the first metal member (510), and a filament (600) being interposed between the first and second metal members. A method for manufacturing a directly heated cathode structure includes the steps of manufacturing a porous pellet (500) having a multiplicity of cavities, welding a first metal member (510) to the lower surface of the porous pellet by a brazing layer (700), impregnating electron radiating material (600) into the cavities of the pellet, and welding a second metal member (520) to the first metal member (510) so that a filament (600) is disposed between the first and second metal members. Life of the cathode structure is prolonged by this because thermions are not emitted through the lower surface of the pellet.