Abstract: In a vacuum electron tube, a novel oxide cathode comprising a metal substrate, means for heating said substrate to its operating temperature, and a layer of alkaline-earth-metal oxide on the substrate. The substrate is essentially free from silicon and contains operative concentrations greater than 1.0 weight % of chromium metal for progressively migrating into the oxide layer and reducing the oxide to yield alkaline-earth-metal.

Abstract: An impregnated cathode comprising a cathode obtained by impregnating pore portions of a refractory porous substrate with an electron emissive material containing Ba and formed thereon a plurality of thin films made of a high melting metal and Sc, or a high melting metal and a Sc oxide, or a high melting metal, Sc and a Sc oxide, or a high melting metal and a compound of Sc, W and O, said thin films having the same composition but different densities can maintain good emission characteristics even after the sealing off step of tube production because the thin films formed on the cathode surface are oxidation-resistant.

Abstract: An indirectly heated cathode structure for electron tubes comprises a cathode supporting sleeve, an electron emission section fitted on a part of the supporting sleeve, and a heater arranged inside the supporting sleeve, the supporting sleeve being an alloy containing niobium as a main component, more particularly more than 85 weight % of niobium. As an additive, at least one metal selected from titanium, zirconium, hafnium, vanadium, tantalum, molybdenum and tungsten is used.

Abstract: A dispenser cathode such as a metal capillary cathode for electrical discharge devices which has a hollow cylindrical head portion 1 which carries a porous emission wafer 3 of a refractive material at its upper end and covers a cathode cartridge 2 which contains an active material supply 4 and comprises an epoxy helical heater 5 surrounded by a metal sleeve 6. Two part division of the structure allows separate testing possibility of the emission wafer and the heater/supply cartridge and also allows an improvement in the heat transmission from the heater to the emission wafer. For this purpose, a hollow cylindrical head portion 1 is conically-shaped and expands outwardly toward the cathode cartridge 2 and the upper part of the cathode cartridge 2 is conically tapered so as to mate with the hollow cylindrical head portion and the two portions are connected together wherein their conical side walls are attached by welding in the upper portion of the drawn up metal sleeve.

Abstract: An electron gun with one directly heatable initial cathode (2), one indirectly heatable second blocking cathode (3) and one focusing electrode (17). The focusing electrode (17) presents an initial centering region (18) and, by means of supporting braces, the blocking cathode (3) is fixed concentrically in a carrier ring (19) presenting a second centering region complementary to the first centering region (18). This permits the blocking cathode (3) to be introduced into the focusing electrode from the back by means of the carrier ring (19), and the carrier ring (19) is secured by means of a locking ring (24).

Abstract: An electron gun assembly for use in a CRT includes a pair of insulating support rods, at least one indirectly heated cathode disposed between the support rods, a heater for the cathode and an improved heater tab. The heater includes a pair of heater legs which are attached to the heater tab. Heater bead straps are provided for attaching the heater tab to the support rods. The electron gun also includes a plurality of electrodes for focusing and accelerating an electron beam generated by the cathode. The improved heater tab comprises a main body portion including a first and a second part. Each of the parts is attached to one of the heater legs. The heater tab has a pair of outwardly directed feet each of which is connected to one of the parts of the main body portion by a pair of substantially orthogonal legs extending therebetween.

Abstract: An inline electron gun for a cathode-ray tube has three cathode assemblies each including a cathode sleeve having a cathode cap closing one end of the sleeve and extending therealong. Each cap has an electron emissive coating thereon and a heater is disposed within each sleeve. The center cathode assembly has a laminated bimetal cathode cap comprising a first layer integral with the sleeve and an overlying second layer with a sidewall portion that is shorter than the sidewall portions of the two outer cathode caps of the outer cathode assemblies. The center cap thus has less thermal mass than the outer caps and the center cathode assembly therefore reaches electron emission temperature before the outer cathode assemblies.

Abstract: A reactionless thermionic cathode for electronic tubes consists of a metallic or ceramic support and an alloy, preferably an intermetallic compound, containing the actual emission-promoting element, with a metal from the group comprising those of the VIIIth vertical row of the periodic table and rhenium. The preferred activation substances are platinides of the elements having a low electron work function, predominantly Ba and La. The cathode is manufactured by wet-mechanical, cataphoretic or electroplating application of the activation substance to the support or by infiltration of the porous support having a pore volume of at least 10%. High emission current densities are obtained at relatively low operating temperatures.

Abstract: Disclosed is a heater for indirect-heated cathode having a heating element composed of a wire with a high specific resistance, such as titanium or titanium-based alloy, around which another wire with a low specific resistance is wound, and having a heat-resisting insulating material covering at least part of said heating element.

Abstract: In a mounting device for electrically heated, spirally wound wire cathodes in electron guns, two mounting posts joined together by an insulator are configured as sector-shaped sections of a hollow cylinder, and have each a circumferential groove on its end remote from the insulator. The surfaces defining the grooves are parts of common circular and cylindrical surfaces, and the mounting ends of the cathodes are of a configuration approximately complementary to that of the grooves in the mounting posts. The mounting ends therefore lie in a spring-biased and form-fitting manner in the circumferential grooves.

Abstract: A method of manufacturing a cathode for magnetron comprises a cathode sleeve formed as a hollow cylinder, a heater inside the sleeve, two end shields formed around the sleeve at a prescribed interval and an electron emitting material applied around the sleeve between both end-shields, wherein a plurality of isolated projections are almost regularly and intergraly formed around the sleeve between the end-shields, and the above electron emitting material is applied onto the cathode sleeve to fill gaps among the plural projections.According to the method of manufacturing a cathode of the present invention, the efficiency of electron emission and electric conductivity are not lowered, whereby the stable operation can be realized for a long term.

Abstract: Disclosed are a method and apparatus for rapidly heating a thermionic vacuum tube cathode, thereby enabling the vacuum tube to be placed in useful operation shortly after the tube is switched on. Rapid heating of the cathode is achieved by passing current through the cathode, thereby directly heating it. Simultaneously, the cathode is also heated by an indirect radiant heater and by electron bombardment by electrons emitted from the heater. When the cathode reaches its operating temperature, the direct heating current and the electron bombardment are stopped and the cathode is maintained at its operating temperature by the indirect heater alone. Cathode warm-up times of less than 1 second may be attained using this invention.

Abstract: An indirectly heated cathode structure for use in cathode ray tubes containing a hollow sleeve of cylindrical shape wherein one edge portion of the sleeve is folded outwardly and backwardly around and against the sleeve. A cap having a circular surface surrounded by a circular sidewall is disposed over the folded edge portion of the sleeve. The sidewall contains an annularly shaped ledge extending around an interior surface portion thereof upon which an end of the folded edge portion of the sleeve rests so as to increase the resistance of the cap to push-off forces applied thereto when the sleeve is restrained. A method for forming the foregoing structure is also disclosed.

Abstract: An indirectly heated cathode including a conductive cup having a closed end provided with an exterior surface coating of electron emissive material and an electrically insulated heater element disposed axially within the cup. The heater element comprises a coaxial pair of outer and inner filamentary coils wound helically in electrical series from a single strand of electrical wire and having integral interconnecting portions adjacent the closed end of the cup for resiliently supporting the inner coil within the outer coil and in alignment with the central portion of the electron emissive coating.

Abstract: A field emission type electron gun comprises a cathode, a plurality of anodes opposing in series to the cathode and a filament for heating the anodes, all being contained in a vacuum tube. The filament is placed immediately before a first anode directly opposing the cathode in a symmetrical manner so as to serve both as a gas expelling member and as an anode.

Abstract: A method of manufacturing a scandate dispenser cathode having a matrix at least the top layer of which at the surface consists substantially of tungsten (W) and scandium oxide (Sc.sub.2 O.sub.3) and with emitter material in or below said matrix. If said method comprises the following steps:(a) compressing a porous plug of tungsten powder(b) heating said plug in a non-reactive atmosphere and in contact with scandium to above the melting temperature of scandium,(c) cooling the plug in a hydrogen (H.sub.2) atmosphere(d) pulverizing the plug to fragments(e) heating said fragments to approximately 800.degree. C. and firing them at this temperature for a few to a few tens of minutes in a hydrogen atmosphere and slowly cooling in said hydrogen atmosphere(f) grinding the fragments to scandium hydride-tungsten powder (ScH.sub.2 /W)(g) compressing a matrix or a top layer on a matrix of pure tungsten from said ScH.sub.

Abstract: A thermionic cathode (FIG. 1) comprises an emitter (3) comprising a matrix (4) of tungsten impregnated with an alkaline earth activator. The matrix is coated with a coating (5) of about 20-30% osmium fully alloyed with tungsten formed by cosputtering osmium and tungsten onto the matrix. A diffusion barrier (6) of osmium may be interposed between the matrix 4 and coating (5) (FIG. 2) and, optionally, osmium may be diffused into the matrix (4). Alternatively the whole matrix may comprise a mixture of about 20-30% osmium fully alloyed with tungsten (FIG. 3). Alternative to osmium and tungsten may be used, and various modifications may be made, and other methods of making the emitter may be used. In particular the proportion of osmium may be about 40%.

Abstract: A cathode assembly for a vacuum tube includes a wire filament, a straight bular anode parallel to and surrounding the wire filament, and insulating spacers for rigidly fastening the filament with respect to the anode, and with one side of the anode indented or flattened such that only one portion of the anode is heated to emitting temperatures by the filament.

Abstract: A cathode structure of a thermal electron emitting cathode of an electron tube, particularly of a magnetron for preventing the damage and break due to mechanical vibration of the cathode. A spacer is interposed in a space between a center lead and a lower end shield to prevent the vibration through the center lead. The antivibration effect of the filament cathode is attained by arranging the spacer having an aperture through which the center lead and a side lead extend such that the spacer contacts to an inner wall of a shielding member which constitutes a portion of a vacuum envelope of the magnetron.

Abstract: In a cathode-ray tube an inline electron gun assembly includes a center cathode assembly disposed between two outer cathode assemblies. The center cathode assembly and the outer cathode assemblies each comprise a tubular cathode sleeve having oppositely disposed ends, a filament disposed within the sleeve and spaced therefrom, and a cathode eyelet coaxially surrounding at least a portion of the cathode sleeve. The cathode sleeve is open at one end and closed at the other end by a cap having an electron emissive material thereon. The open end of the cathode sleeve is attached to the interior surface of the eyelet. At least a portion of the interior surface of at least one of the eyelets is modified to change the radiant energy emission characteristics thereof.

Abstract: A heater and support structure for a line cathode includes heater electrodes and an S-shaped cathode support member arranged between the heater electrodes. The heater electrodes and the S-shaped support member have a higher resistance than the cathode and thus heat flows into the cathode to compensate for heat radiation losses and the support compensates for thermal expansion to retain the cathode at a substantially constant position.

Abstract: A cathode structure includes a thermal conductive member, a heater for heating a thermal conductive member, a metal substrate having a first surface facing a thermal conductive member and a second surface and attached to the thermal conductive member to form a space between a central portion of a second surface and the thermal conductive member, and an electron emitting member provided on a second surface of a metal substrate.

Abstract: A cathode filament formed from a thin metal wire wound into a helical spiral is welded at its two ends to connection braces by means of a high energy beam such as a laser beam. By increasing the pitch of at least one of the turns near each of the two ends, welding is confined to a predefined number of turns and uniformly welded cathodes are obtained having filament resistances which differ by less than 1%.

Abstract: Electron emissive material is applied to a line cathode by surrounding the cathode with cylinders at the locations where deposition of the material is desired and voltage biasing the cylinders positive with respect to the line filament for a prescribed time.

Abstract: I have discovered that an electron beam emitted from an LaB.sub.6 single crystal cathode has higher brightness when a significant portion of the actual emitting surface of the LaB.sub.6 crystal comprises flat surfaces oblique to the electron beam axis and when these flat surfaces expose relatively low work function crystal planes. I have defined as a relatively low work function crystal plane those crystal planes having a lower work function than the average work function for sintered LaB.sub.6. My preferred geometry for a single crystal LaB.sub.6 electron emitting tip is a pyramid oriented such that the apex points in the electron beam emission direction and preferably also points in a direction perpendicular to a relatively low work function crystal plane. The pyramidal tip may have three, four, or more flat sides, all of which contribute electrons to the beam, from at least an area in the vicinity of the apex. The apex of the pyramid may be rounded or flat.

Abstract: A tungsten filament intended as a thermionic source, made from a wire of which the zone defining the point is of a diameter smaller than that of the basal zone and where the diameter of the transitory part of the wire changes progressively. This filament is contained in the same plane and its lower legs are welded to rigid posts in a ceramic base. A novel electrolytic sharpening process is used for the reduction of the diameter of the filament wire, and this process, which permits the progressive reduction of the dimension of a workpiece, can be used in other applications. An apparatus is used for the manufacturing of such a filament by cyclic electrolytic sharpening, as well as means enabling the bending of the wire and its positioning during the welding operation.

Abstract: To achieve an optimum reduction of the warmup time of a Wehnelt cathode, by maintaining a good efficiency, it is proposed to use as a cathode a triode system arranged within the usual cathode sleeve, with the inside of the base plate, on the outside of which the electron-emitting layer is deposited, serving as the anode, so that the electron-emitting layer is heated by the anode dissipation of the triode system.

Abstract: A one-piece, directly heated cathode is disclosed for use in a cathode ray tube electron gun. The cathode according to the invention has the configuration of a hollow cylinder with one closed end for receiving a thermionic electron-emissive coating. A pair of body portions extending axially in the same direction from diametrically opposed sides of the closed end define two legs which act as serial electrical conductors having inherent resistance for use in resistively heating the electron-emissive coating. The legs have an arcuate cross-section effective to structurally stabilize the cathode and suppress temperature-induced lateral displacement of the cathode which would otherwise degrade the performance of the electron gun.

Abstract: A controlled porosity sheet defining a surface for a thermionic dispenser thode and a method of manufacture. Starting with a generally flat silicon template substrate structure having an array of upstanding microposts 1-25 microns across on 5-100 micron spacings from each other, a layer of metal is deposited on the substrate to surround the microposts and cover the substrate structure to a desired depth. The metal layer is then abraded to a smooth, flat surface which exposes the microposts. Thereafter, the silicon substrate and microposts are completely etched away, leaving a metal sheet having micron-size holes therethrough.

Abstract: In a cathode heater, the portion of the coil adjacent to the emitting surface of the cathode has a smaller pitch or is covered with an oxide coating of lower capacity of heat per unit of length than the distant portion. As a result, the emitting surface is heated-up very quickly, and in a picture tube, for example, the picture comes on after a very short time. The heater according to the invention can be exchanged for a conventional heater without electrical and mechanical changes.

Abstract: A compressed dispenser cathode having 1-15% by weight of Ba.sub.2 Sc.sub.2 O.sub.5 in a porous metal cathode body has an emission having a larger current density (exceeding 6 A/cm.sup.2) and a longer life (more than 3000 hours).

Abstract: A thermionic cathode supporting device which comprises an electroconductive member adapted to support a thermionic cathode tip and a tip supporting heaters which hold said tip, a pressing means for resiliently pressing the above mentioned members from the outside thereof. The device is so arranged that the pressing force is easily adjustable and can be miniaturized, and applicable for the various different types of cathode devices of an electron gun or the like.

Abstract: In an exemplary embodiment, a metal capillary cathode for electric discharge vessels with an emission substance carrier disk porous on its front face and comprised of metal melting at a high temperature is constructed to prevent lateral emission of electrons (interfering emission). To this end, the disclosure provides that the emission substance carrier disk has a nonporous outer casing surface with a higher electron work function than the outer, active surface of the emission substance carrier disk. Such a dispenser cathode is employed as a metal capillary cathode in traveling wave tubes.

Abstract: A directly heated type cathode assembly comprises a ribbon filament to a substantially central portion of which an electron-emitting substance is attached through a metal plate, a first support member on which one end portion of the ribbon filament is fixed to support the ribbon filament, the first support member being electroconductive, a second support member for supporting that portion of the ribbon filament which is a little short of the other end of the ribbon filament, a conductive spring member fixed to the other end portion of the ribbon filament, and a conductive cathode cylinder supporting the first support member, second support member and spring member and having a base at the filament side, the base of the cylinder having at least one opening.

Abstract: A reaction thermionic cathode of the diffusion type on the basis of an activated high-temperature support metal doped with a diffusion-promoting additive for the activator substance, provided with a barrier layer inhibiting the self-diffusion of this additive in an undesired direction.

Abstract: Presented is a cathode-heater assembly including a support structure for the cathode-heater assembly that is particularly rugged in that it resists displacement of the cathode-heater assembly in all planes, and minimizes power requirements to raise the cathode to operating temperature.

Abstract: A magnetron includes an evacuated envelope having a sealing flange attached thereto, a filament electrode within the envelope and an anode electrode surrounding the filament electrode. One end of the filament electrode is electrically connected to a filament flange assembly. The other end of the filament electrode is connected to a filament post assembly which is insulated from the filament flange assembly. The filament flange assembly has a radially projecting, substantially flat annular sealing flange extending therefrom. The annular sealing flange of the filament flange assembly is hermetically joined to the envelope. Electrical connections to the filament electrode are made by means of a pair of substantially rectangular terminals having a flat contact surface attached to the filament flange assembly and the filament post assembly respectively.

Abstract: A large cathode structure having a diameter on the order of 50 cm for producing uniform plasmas in a magnetic field. The cathode is oxide-coated and indirectly heated by a plurality of heater wires disposed in insulating tubes arranged parallel to each other. The cathode is pressed against the insulating tubes thereby to maintain it substantially flat in spite of expansion and contraction due to the heating and cooling effects. Optionally, the insulating tubes carrying the heater wires may be backed up by a second set of insulating tubes disposed at right angles to the first set. An annular ring is disposed about the cathode and is provided with tungsten springs for forcing the cathode against the heater tubes. This ring may additionally serve as a heat shield and maintain the temperature more uniform about the periphery of the cathode. For large cathodes, the structure may be water cooled by the provision of two copper tubes through which the water flows.

Abstract: An indirectly-heated cathode device for electron tubes, comprising a hollow cathode sleeve of thin wall, a base metal mounted to one end of the sleeve and having the surface coated with an electron-emitting material, and a heater mounted within the sleeve. The sleeve is made of Ni-Cr alloy containing 2 to 35% by weight of Cr and predetermined amounts of additives including Co, W, Mo and/or Fe.

Abstract: In a thermionic cathode having a planar emissive body and a heating element of pyrolytic graphite which is provided on the side of the emissive body remote from the emissive surface of the emissive body, a uniform temperature distribution adjusts during operation throughout the overall emissive surface when the heating element is planar and the crystallographic c-axis of the pyrolytic graphite extends everywhere normal to the surface of the heating element facing the emissive body. As a result of this the possibility is obtained of realizing a planar, "rapid", induction-free unipotential cathode having a substantially ideal homogeneous temperature distribution.

Abstract: An electrically resistive heater consisting of a helix of resistive wire, the helix being shaped into a toroid or a spiral, with the electrical return lead extending coaxially through the helix so as to provide a magnetic field of equal magnitude and opposite sense to that produced by current in the helix to cancel the magnetic fields.

Abstract: The magnetron tube is provided with two concentric supports each with one end connected to the opposite ends of the cathode electrode and two concentric cup shaped input terminals respectively connected to the other ends of the supports. Lead wires extending from a filter for preventing leakage of high frequency wave are welded to the edges of the cup shaped input terminals and clamped thereto at portions near the welded ends by clamping members.

Abstract: The performance of microwave tubes at very high frequencies is limited by the ability of their thermionic cathodes to provide high emission current density in combination with long life and low evaporation of active material. An improved tube uses a cathode comprising a porous metal matrix consisting of a compacted mixture of tungsten and iridium particles, impregnated with a molten barium aluminate. Other alkaline earth oxides may be used as additives. The impregnated cathode outgasses easily and has a long life because it is not dependent on thin surface films. Thermionic emission is improved compared to a tungsten matrix, and barium evporation is reduced. The combination of power and frequency obtainable from the microwave tube is thereby significantly increased.

Abstract: A thermionic electron emitter comprises a tube of wall thickness less than 0.1 mm, a body of thermionic electron emissive material compressed and sintered in the tube, and a ring, coaxial with the tube, within the body to provide constraint against cracking of the body.

Abstract: A cathode structure for an electron tube comprises a filament unit and a supporter on which the filament unit is mounted. The filament unit includes a thoriated tungsten wire and a tungsten carbide layer formed by carburizing the surface of the wire, the wire having a diameter of about 0.6 - 0.8 mm and the carbide layer having a thickness of about 5 - 30 .mu., so that the resulting cathode structure enjoys a long life.

Abstract: Electronic device comprising an evacuated envelope containing a main thermionic cathode heated solely by energetic electrons emitted from an unheated auxiliary field-emission cathode.

Abstract: Cathode cup has a stop shoulder therein. Cathode is spring urged against the stop shoulder so that it is retained in position through mechanical shock and thermal cycling. The method of assembling the cathode structure includes the step of compressing the spring loaded structure and staking the cathode cup behind the spring.

Abstract: A line electron filament is provided which is cylindrically shaped and substantially uniform in cross section about its longitudinal axis. The filament can be of the type known as directly heated or of the type known as indirectly heated. The uniformity of the filament is obtained through cataphoretic deposition in a rotating cylindrical tube. The filament is useful as a cathode in a display which employs space charge limited emission operation.

Abstract: A thermionic heater cathode assembly of an electron-beam gun, comprising a disc cathode made of a highly-emissive material and disposed near a U-shaped ribbon filament with a thermionic portion and current-carrying sections arranged in parallel, wherein the ends of said ribbon filament sections to be connected to a holder are arranged in a plane normal to the ends of the same sections, adjoining the thermionic portion of said ribbon filament.

Abstract: Disclosure is made of a cathode assembly of an electron beam welding gun, wherein in a holder's sleeve, which is mounted an a current lead, there is arranged a disc cathode. Arranged in the cavity of said current lead, coaxially therewith, are two more current leads. The latter two current leads are concentric to each other; in said current leads there is secured a flat coil with a central end bent at a perpendicular to the coil's plane. Said central end, bent at a perpendicular to the coil's plane, is corrugated along its axis and installed in a current lead constructed as a rod having a stepped cavity extending along the rod's axis. The outer turn of said coil is arranged in another current lead which envelops the above-mentioned current lead and is constructed as a tube with an internal annular recess at its end, which receives the outer turn of said coil.