US3591822A - Electric discharge vessel electrode structure of pyrolytic carbon discs - Google Patents

Electric discharge vessel electrode structure of pyrolytic carbon discs Download PDF

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Publication number
US3591822A
US3591822A US783328A US3591822DA US3591822A US 3591822 A US3591822 A US 3591822A US 783328 A US783328 A US 783328A US 3591822D A US3591822D A US 3591822DA US 3591822 A US3591822 A US 3591822A
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United States
Prior art keywords
carbon
improvement according
metal layer
rhenium
metal
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Expired - Lifetime
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US783328A
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English (en)
Inventor
Helmut Katz
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Siemens AG
Siemens Corp
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Siemens Corp
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Publication date
Priority claimed from DE19671614680 external-priority patent/DE1614680C3/de
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
    • C04B41/52—Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81—Coating or impregnation
    • C04B41/89—Coating or impregnation for obtaining at least two superposed coatings having different compositions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/28—Non-electron-emitting electrodes; Screens
    • H01J19/30—Non-electron-emitting electrodes; Screens characterised by the material
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/90—Electrical properties
    • C04B2111/94—Electrically conducting materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H01J2893/002—Chemical composition and manufacture chemical
    • H01J2893/0021—Chemical composition and manufacture chemical carbon

Definitions

  • a high frequency power tube is provided with an electron gun in which the thermally heavy-duty electrodes and other parts thereof are provided as carbon bodies made of pyrolytical carbon interconnected in the form of discs which are coated with rhenium, and which for better conductivity ,are additionally coated with a metal of high electrical conductivity, preferably copper or silver.
  • This invention relates to electric discharge vessels, and more particularly to electrode structures for electric. discharge vessels which are provided with an electron gun, for example high frequency power tubes, wherein the electrodes, parts of electrodes, or other parts of the electron gun which are located within the tube comprise carbon.
  • Carbon is a material which withstands the highest temperatures and which has a high melting point as well as a low vapor pressure.
  • carbon has a very high radiation capacity which is not far from the radiation capacity of a black body.
  • carbon bodys can be heated locally to very high temperatures and the heat thereof may be dissipated to the neighboring region through radiation.
  • a highly annealing body can also work as an excellent grid when provided with a suitable coating of a metal such as zirconium at points particularly suitable therefore.
  • the secondary emission of carbon bodies is very small, particularly when their surfaces are roughly finished. Also, it is easy to process carbon mechanically and to provide carbon elements in practically any desired shape.
  • an electric discharge vessel wherein an electron gun is provided with heavy-duty electrodes, parts of the electrodes or other parts made of carbon, these parts comprising pyrolytic carbon with anisotropic properties with respect to heat conductivity such that the good heat conductivity occurs outwardly in the direction of the exterior of the tube, particularly at right angles to the axis of the tube.
  • the carbon bodies with dimensions greater than mm. in the direction of poor heat conductivity comprise a plurality of thin discs which are interconnected by interlinings of metal rings and/or metal foils of molybdenum or tantalum which have high melting points.
  • FIG. 1 is a fragmentary sectional view of an embodiment of an electrode according to the invention.
  • FIG. 2 is a fragmentary sectional view of another embodiment of electrode construction according to the invention.
  • a base 1 of carbon carries a metal layer 2 which is preferably rhenium because of its ease of deposition, high den sity, high melting point and its advantage of not forming a carbide with the carbon base I.
  • a second metal layer 3, preferably copper or silver, increases the electrical conductivity of the electrode.
  • FIG. 2 illustrates the construction of an electrode from a plurality of carbon bodies 4. Interlayers 5, 6 of molybdenum or tantalum are electron welded to bond the carbon bodies 4 together. If desired, the electrode so formed may have on its outer surfaces (not shown) layers of rhenium and/or other high conductivity material.
  • pyrolytic carbon or graphite is defined herein to mean carbon which is deposited in layers by thermal heating on hot surfaces of suitable carbon compounds, more particularly hydrocarbons. Pyrolytic carbon shows such a pronounced anisotropy with respect to its capacity for thermal conduction that'the thermal conduction in one direction approximates at least the thermal conduction of copper, while thermal conduction is much smaller in the other direction. The extent of anisotropy approximates the value of 200.
  • the heat generated perpendicular to the axis of the tube is dissipated much more rapidly by the shortest route to the outside of the tube or to a cooling medium than along the axis of the'tube.
  • the extremely high heat carrying capacity in other words, the high melting point as well as the low vapor pressure of the carbon, is thereby a particular advantage. It has been determined that the pyrolytic carbon according to its entire layer construction can very easily be made in discs if the direction of poor thermal conductivity lies in the direction of the disc axis (thickness), whereby the practical thickness ofv the disc is in the range of approximately 3 to 10 mm.
  • Electrodes, or parts of electrodes, having a dimension greater than 10 mm. in the axial direction, that is in the direction of the poor thermal conductivity, are therefore constructed with interlining metal rings or metal foils from a corresponding number of discs. These rings are welded together,
  • discs with corresponding, particularly varying, dimensions can be employed in order to provide a predetermined inner or outer contour of the-electrode in question.
  • the pyrolytic carbon on the points in question can be provided on the surfaces with a metal-layer, preferably of rhenium.
  • rhenium can likewise be applied in similar fashion as rhenium, which have a still better electrical conductivity.
  • rhenium is preferred in that it has the substantial advantage that it does not form a carbide with the carbon body as a foundation material, so that it does not need an additional interlining. It can easily be deposited in a chemical reductive process and, above all, it produces very dense layers.
  • other metal layers to be provided which have a higher electric conductivity, are most advantageously additionally applied on a surface already coated with rhenium, for example, by electrolysis.
  • this step nevertheless has a substantial advantage over the direct use of copper, since during operation of the tube, if there is an un desirable impact of the electron beam, only the'copper layer is destroyed but not the base. Therefore, the rhenium. and the carbon are'not altered and a destruction of the form of the apparatus cannot occur. Small regions of insignificant conductivity may arise, however, such small regions do not affect the function of the tube.
  • An electrode structure for use within an electric discharge vessel, said structure being subjected to operation under high temperature conditions, the improvement comprising the provision of said structure as comprising a carbon base having a longitudinal axis and a thermal anisotropic characteristic which provides for good heat conductivity in a direction of short distance to the outside of the vessel perpendicular to said axis and having poor heat conductivity in the direction parallel to said axis, said carbon base comprising a plurality of adjacently disposed carbon discs each of which includes at least one surface which faces a similar surface of an adjacent carbon discs, and a plurality of metal interlinings bonding said facing surfaces.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Discharge Heating (AREA)
  • Microwave Tubes (AREA)
US783328A 1967-12-13 1968-12-12 Electric discharge vessel electrode structure of pyrolytic carbon discs Expired - Lifetime US3591822A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19671614680 DE1614680C3 (de) 1967-12-13 1967-12-13 Elektrisches Entladungsgefäß, insbe sondere HF Leistungsrohre

Publications (1)

Publication Number Publication Date
US3591822A true US3591822A (en) 1971-07-06

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Family Applications (1)

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US783328A Expired - Lifetime US3591822A (en) 1967-12-13 1968-12-12 Electric discharge vessel electrode structure of pyrolytic carbon discs

Country Status (3)

Country Link
US (1) US3591822A (enrdf_load_stackoverflow)
FR (1) FR1593831A (enrdf_load_stackoverflow)
GB (1) GB1237948A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2199013A1 (enrdf_load_stackoverflow) * 1972-09-08 1974-04-05 Siemens Ag
US3878425A (en) * 1972-09-08 1975-04-15 Siemens Ag Vacuum - tight carbon bodies
FR2398381A1 (fr) * 1977-07-21 1979-02-16 Philips Nv Tube electronique comportant une cathode a incandescence
US4302701A (en) * 1978-07-07 1981-11-24 Siemens Aktiengesellschaft Directly heated cathode for an electron tube with coaxial electrode design
US4392238A (en) * 1979-07-18 1983-07-05 U.S. Philips Corporation Rotary anode for an X-ray tube and method of manufacturing such an anode
US4647748A (en) * 1984-05-17 1987-03-03 Smith International, Inc. Graphite electrode construction and method of making
US5220575A (en) * 1989-04-04 1993-06-15 Doduco Gmbh + Dr. Eugen Durrwachter Electrode for pulsed gas lasers

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2030695A (en) * 1932-05-07 1936-02-11 Erber Bernhard Electric lamp
DE1191494B (de) * 1961-09-29 1965-04-22 Siemens Ag Elektrode aus einem Verbundmetall fuer elektrische Entladungsgefaesse, insbesondere hochbelastbare Anode
US3307063A (en) * 1962-03-02 1967-02-28 Thomson Houston Comp Francaise Grid electrode made of pyrolytic graphite
US3320467A (en) * 1963-10-01 1967-05-16 Raytheon Co Pyrographite wave structures
US3476586A (en) * 1962-04-16 1969-11-04 Metalurgitschen Z Lenin Method of coating carbon bodies and the resulting products

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2030695A (en) * 1932-05-07 1936-02-11 Erber Bernhard Electric lamp
DE1191494B (de) * 1961-09-29 1965-04-22 Siemens Ag Elektrode aus einem Verbundmetall fuer elektrische Entladungsgefaesse, insbesondere hochbelastbare Anode
US3307063A (en) * 1962-03-02 1967-02-28 Thomson Houston Comp Francaise Grid electrode made of pyrolytic graphite
US3476586A (en) * 1962-04-16 1969-11-04 Metalurgitschen Z Lenin Method of coating carbon bodies and the resulting products
US3320467A (en) * 1963-10-01 1967-05-16 Raytheon Co Pyrographite wave structures

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2199013A1 (enrdf_load_stackoverflow) * 1972-09-08 1974-04-05 Siemens Ag
US3878425A (en) * 1972-09-08 1975-04-15 Siemens Ag Vacuum - tight carbon bodies
FR2398381A1 (fr) * 1977-07-21 1979-02-16 Philips Nv Tube electronique comportant une cathode a incandescence
US4178530A (en) * 1977-07-21 1979-12-11 U.S. Philips Corporation Electron tube with pyrolytic graphite heating element
US4302701A (en) * 1978-07-07 1981-11-24 Siemens Aktiengesellschaft Directly heated cathode for an electron tube with coaxial electrode design
US4392238A (en) * 1979-07-18 1983-07-05 U.S. Philips Corporation Rotary anode for an X-ray tube and method of manufacturing such an anode
US4647748A (en) * 1984-05-17 1987-03-03 Smith International, Inc. Graphite electrode construction and method of making
US5220575A (en) * 1989-04-04 1993-06-15 Doduco Gmbh + Dr. Eugen Durrwachter Electrode for pulsed gas lasers

Also Published As

Publication number Publication date
FR1593831A (enrdf_load_stackoverflow) 1970-06-01
GB1237948A (enrdf_load_stackoverflow) 1971-07-07

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