EP3764386A1 - Ringförmige kathode für elektronische röhre - Google Patents

Ringförmige kathode für elektronische röhre Download PDF

Info

Publication number
EP3764386A1
EP3764386A1 EP20183040.3A EP20183040A EP3764386A1 EP 3764386 A1 EP3764386 A1 EP 3764386A1 EP 20183040 A EP20183040 A EP 20183040A EP 3764386 A1 EP3764386 A1 EP 3764386A1
Authority
EP
European Patent Office
Prior art keywords
cathode
electron emitter
annular
folded skirt
support
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP20183040.3A
Other languages
English (en)
French (fr)
Inventor
Alberto LEGGIERI
François LEGRAND
Rodolphe Marchesin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
Thales SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thales SA filed Critical Thales SA
Publication of EP3764386A1 publication Critical patent/EP3764386A1/de
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01J19/02—Electron-emitting electrodes; Cathodes
    • H01J19/04—Thermionic cathodes
    • H01J19/10—Thermionic cathodes characterised by the shape
    • H01J19/12—Supports; Vibration-damping arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/02—Electrodes; Magnetic control means; Screens
    • H01J23/04—Cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/13—Solid thermionic cathodes
    • H01J1/15—Cathodes heated directly by an electric current
    • H01J1/16—Cathodes heated directly by an electric current characterised by the shape
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/13—Solid thermionic cathodes
    • H01J1/15—Cathodes heated directly by an electric current
    • H01J1/18—Supports; Vibration-damping arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/88—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
    • 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
    • H01J19/42—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
    • 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
    • H01J19/42—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
    • H01J19/48—Mountings for individual electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/02—Electrodes; Magnetic control means; Screens
    • H01J23/06—Electron or ion guns
    • H01J23/07—Electron or ion guns producing a hollow cylindrical beam
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/34—Travelling-wave tubes; Tubes in which a travelling wave is simulated at spaced gaps
    • H01J25/42—Tubes in which an electron stream interacts with a wave travelling along a delay line or equivalent sequence of impedance elements, and with a magnet system producing an H-field crossing the E-field

Definitions

  • thermoelectric / thermionic electron guns such as gyrotrons.
  • a gyrotron is a power electronic tube (oscillator), generating a microwave wave.
  • cathode electron emitters The main disadvantage of cathode electron emitters is contact with the element that supports it.
  • the electron emitter must be kept in a specific position, but at the same time must be thermally insulated from the rest of the cathode (including the holder). In addition, the electron emitter must have a homogeneous temperature over the entire surface.
  • the contact of the emitter, with the structure which supports it, is therefore very important, because it creates several zones having temperature discontinuities, also resulting in asymmetric thermal deformations. This inhomogeneity and these deformations affect the quality of the beam emitted by the electron gun.
  • Such an embodiment compensates for longitudinal expansion of the electron emitter without compensating for radial and orbital expansions, which involves deformation of the electron emitter by anisotropic thermal expansion. These expansions are not balanced and there is an inhomogeneity of thermal expansion. At the same time, the presence of discrete contact points between the electron emitter and traditional connections produces discontinuities in heat flow and affects the thermal homogeneity of the emitter.
  • the main difficulties in designing a cathode relate to the alignment of the electron emitter and the thermal insulation between the electron emitter and other parts of the cathode, especially with the element that supports the. transmitter.
  • the electron emitter must be placed in a certain position, therefore, an element is dedicated to its support, hereinafter called the support.
  • the existing cathodes have, in terms of alignment of the emitters, the following main drawbacks.
  • the support is sensitive to the deformations induced by the thermal expansion of the materials. These deformations compromise the alignment of the support: the mechanical position of the support at room temperature can change after thermal heating. Often the mechanical position of the holder at room temperature cannot match its position when the electron emitter is heated. As a result, the spatial position of the electron emitter can change before, during and after heating.
  • the existing cathodes have, in terms of thermal homogeneity, the following main drawbacks.
  • the support must be in contact, at least partially, with the transmitter. This contact is a mechanical contact, which is therefore a thermal contact.
  • the support elements in contact with the electron emitter allow a flow of heat which creates temperature differences in the contact zone. This temperature difference causes inhomogeneity of the temperature of the electron emitter along the surface of the emitter. This inhomogeneity of the temperature causes an inhomogeneity of the energy of the electrons emitted, which results in a poor quality of the beam.
  • the figure 1 schematically shows a sectional view and a top view of a cylindrical cathode known from the state of the art, comprising a flexible holding element 1 (inclined or conical holding element) which connects an electron emitter 2 to electron-emitting surface concave to the support 3 of the cathode.
  • a flexible holding element 1 inclined or conical holding element
  • the electron emitter 2 expands in the axial direction of the cathode, in the positive direction, while the flexible holding member 1 has a thermal expansion projection in the same axial direction, but in the opposite, negative direction .
  • the longitudinal expansions of the two structures are practically balanced.
  • the radial and orbital expansions are not balanced and the heat flux can be significant at the interface between the electron emitter 2 and the conical holding element 1.
  • the presence of discrete contact points between the electron emitter 2 and the conical holder 1 causes discontinuities in heat flow and affects the thermal homogeneity of electron emitter 2.
  • An aim of the invention is to overcome the problems mentioned above.
  • the present invention improves the alignment and thermal homogeneity of the cathode electron emitter under hot operating conditions.
  • the folded skirt is in one piece.
  • the folded skirt comprises a plurality of concentric tubular cylinders with circular sections, two consecutive cylinders being connected alternately at one end and at the other of the tubular cylinders by a ring.
  • the cylindrical central support has a circular section.
  • the annular cathode includes a leg attachment bracket disposed between the electron emitter and the legs.
  • the legs are U-shaped.
  • the legs are angularly evenly distributed.
  • the thermal homogeneity is improved because the thermal discontinuities are symmetrically distributed in the orbital direction, improving the thermal homogeneity.
  • the volume to surface ratio of a tab and / or of a cylinder of the folded skirt is less than 0.06 mm.
  • a tab has a volume to area ratio of 0.05mm.
  • a cylinder of the folded skirt has a volume to area ratio of 0.025 mm.
  • the proposed invention relies on two coupled mechanical retainers that work synergistically to maintain the concentricity and alignment of all cathode components during hot operation.
  • the two retaining elements are a folded skirt 4 and a plurality of tabs 5 arranged in series between a cylindrical central support 7 with an axis that of the cathode and an external peripheral electron emitter 6 with an annular section with an axis that of the cathode. cathode, extending around the outer periphery of the cathode.
  • the folded skirt 4 makes it possible to compensate for axial and radial deformations of the geometry of the cathode.
  • the folded skirt 4 comprises concentric tubular sleeves or cylinders 4a which implement flexible retaining elements calibrated with opposing thermal expansion vectors to compensate for thermal expansion.
  • the plurality of tabs 5 makes it possible to compensate for orbital and radial deformations of the cathode.
  • the legs 5 are radial supports which connect the outer peripheral electron emitter 6 to the connected skirt 4.
  • Axial compensation can be achieved by adjusting the height (dimension in the axial direction) of the legs.
  • These tabs implement flexible retaining elements which compensate for the radial expansion of the material by an isotropic counter-effect acting on the circumferential direction.
  • the opposite expansion within a symmetrical deformation makes the electron emitter aligned in the desired condition, once the system has been sized to operate that condition.
  • the tubular cylinders 4a of the folded skirt 4 expand in opposite longitudinal and radial directions and, simultaneously, the tabs 5 expand in opposite orbital and radial directions.
  • the presence of the tubular cylinders 4a makes the expansion of the electron emitter 6 balanced in the three directions axial, radial and orbital.
  • the tubular cylinders 4a of the folded skirt 4 expand symmetrically in the axial direction of the annular cathode in both positive and negative directions, as a result of the symmetry of the expanding forces distributed over the sleeves themselves.
  • the temperature discontinuities and the mechanical expansion differences along the tubular cylinders 4a of the folded skirt 4 are greatly limited.
  • the limited thermal conduction between the outer peripheral electron emitter 6 and the holding elements 4, 5 is ensured by the alternation of contact points of reduced size between the holding elements of the device. the electron emitter and the star sleeves.
  • the retaining elements are made from suitable materials (Tungsten, Molybdenum and Moly-Rhenium) and are designed with a constraint on their form factor (reduced volume compared to the surface) in order to limit thermal conduction.
  • thermal homogeneity is ensured by the multiplicity of contact points, which creates thermal discontinuities of small amplitude, each placed in a close space. The result is negligible thermal inhomogeneity of the electron emitter 6.
  • the structure of the retaining elements 4, 5 can be reversed and the number of tubular cylinders 4a of the folded skirt 4 and / or the number of tabs 5 can be adapted for a better match of the sizes of the central support 7 and of the transmitter. of electrons 6 of electrons, depending on the size of the cathode.
  • the tubular cylinders 4a of the folded skirt 4 expand in opposite longitudinal and radial directions and, simultaneously, the star-shaped legs 5 expand in opposite orbital and radial directions.
  • the result of symmetrical deformations in both directions along the three axes makes the electron emitter 6 thermally deformed in a concentric manner and aligned with the rest of the cathode structure.
  • the limited thermal conduction between the electron emitter 6 and the holding elements 4, 5 is ensured by the alternation of contact points of reduced size between the electron emitter 6 and the legs 5, with a conduction thermal given by the material property and the length ratio of the holding elements.
  • the figure 3 schematically illustrates a comparison between an annular cathode of the state of the art and an annular cathode according to one aspect of the invention.
  • the present invention in addition to compensating for thermal expansions, makes it possible to improve the thermal homogeneity of the electron emitter 6.
  • an example of a known solution is compared to the invention proposed on the figure 3 .
  • FIGS 4 and 5 schematically illustrate an annular cathode in top view and in sectional view, according to one aspect of the invention.
  • the folded skirt 4 comprises a plurality of concentric tubular cylinders 4a with circular sections, two consecutive cylinders 4a being connected alternately at one end and at the other of the tubular cylinders by a ring 4b.
  • the electron emitter 6 has an outer surface emitting electrons outwards.
  • the cylindrical central support 7 is tubular with a circular section, and the legs 5 are U-shaped.
  • a support 9 for fixing the tabs 5 is arranged between the electron emitter 6 and the tabs 5.
  • the support 9 is provided with locations, such as slots, intended to receive the ends of the tabs 5, by sliding, which then it suffices to fix by simple soldering. This simplifies the fixing of the tabs 5 on the electron emitter 6.
  • the figure 6 schematically illustrates an example of a leg and a cylinder.
  • the volume to surface ratio of a tab and / or of a cylinder of the folded skirt may be less than 0.06 mm.
  • a tab 5 has a volume to area ratio of 0.05 mm
  • a cylinder 4a of the folded skirt 4 has a volume to area ratio of 0.025 mm.

Landscapes

  • Electrodes For Cathode-Ray Tubes (AREA)
  • Solid Thermionic Cathode (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
EP20183040.3A 2019-07-08 2020-06-30 Ringförmige kathode für elektronische röhre Pending EP3764386A1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1907279A FR3098640B1 (fr) 2019-07-08 2019-07-08 Cathode annulaire pour tube electronique

Publications (1)

Publication Number Publication Date
EP3764386A1 true EP3764386A1 (de) 2021-01-13

Family

ID=68733180

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20183040.3A Pending EP3764386A1 (de) 2019-07-08 2020-06-30 Ringförmige kathode für elektronische röhre

Country Status (4)

Country Link
US (1) US11011338B2 (de)
EP (1) EP3764386A1 (de)
CN (1) CN112331543A (de)
FR (1) FR3098640B1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114023617A (zh) * 2021-11-02 2022-02-08 电子科技大学 一种基于冷阴极的环形多电子注辐射源

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114883161A (zh) * 2022-03-25 2022-08-09 中国电子科技集团公司第十二研究所 一种速调管电子枪用阴极热子组合件

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3631290A (en) 1970-08-17 1971-12-28 Ibm Thermionic cathode for electron beam apparatus
FR2532468A1 (fr) * 1982-08-31 1984-03-02 Thomson Csf Perfectionnement aux cathodes a chauffage direct

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2928978A (en) * 1956-08-03 1960-03-15 Int Standard Electric Corp Mounting of thermionic cathodes
US3265919A (en) * 1961-05-26 1966-08-09 Gen Electric Electric discharge device with improved electrode support
US3824424A (en) * 1973-03-26 1974-07-16 Varian Associates Mesh type filamentary thermionic cathode emitter and tube using same
US4954745A (en) * 1989-03-22 1990-09-04 Tektronix, Inc. Cathode structure
GB9405139D0 (en) * 1994-03-16 1994-05-18 Eev Ltd Electron gun arrangements
FR2762712B1 (fr) * 1997-04-25 2004-07-09 Thomson Tubes & Displays Structure de cathode pour tube a rayons cathodiques
GB2337151B (en) * 1998-05-09 2002-08-28 Eev Ltd Electron gun arrangements
FR2810789A1 (fr) * 2000-06-21 2001-12-28 Thomson Tubes & Displays Cathode a rendement thermique optimise

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3631290A (en) 1970-08-17 1971-12-28 Ibm Thermionic cathode for electron beam apparatus
FR2532468A1 (fr) * 1982-08-31 1984-03-02 Thomson Csf Perfectionnement aux cathodes a chauffage direct

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114023617A (zh) * 2021-11-02 2022-02-08 电子科技大学 一种基于冷阴极的环形多电子注辐射源
CN114023617B (zh) * 2021-11-02 2023-01-31 电子科技大学 一种基于冷阴极的环形多电子注辐射源

Also Published As

Publication number Publication date
CN112331543A (zh) 2021-02-05
US11011338B2 (en) 2021-05-18
FR3098640A1 (fr) 2021-01-15
FR3098640B1 (fr) 2021-11-26
US20210012994A1 (en) 2021-01-14

Similar Documents

Publication Publication Date Title
EP3764386A1 (de) Ringförmige kathode für elektronische röhre
EP0982976B1 (de) Auf hohen thermischen Belastungen abgestimmter Plasmamotor mit geschlossenem Elektronendrift
JP6260409B2 (ja) 太陽熱集熱装置の製造方法
JPH11224627A (ja) ストラドルベアリングアセンブリー
FR3035937A1 (fr) Systeme de frein
FR2877489A1 (fr) Canon a electrons
EP3223591B1 (de) Anschlussvorrichtung zwischen synchrotron-ringabschnitten
EP1432073A1 (de) Koaxiale kolineare Antenne
EP0107522B1 (de) Direkt geheizte Kathoden
CA2319620C (fr) Grille pour tube electronique a faisceau axial
FR2641414A1 (fr) Tube a faisceau d'electrons refroidi partiellement par rayonnement direct
WO2001099140A1 (fr) Cathode a rendement thermique optimise
EP1363083B1 (de) Doppeltrohrwärmetauscher mit verstärktem Kontakt
FR2833749A1 (fr) Refroidissement d'un tube electronique
JP2019220268A (ja) 電子銃
FR3040735A1 (fr) Carter de turbine haute-pression d'une turbomachine a refroidissement localise
FR2606937A1 (fr) Ligne a retard a couplage par cavites pour tube a onde progressive
JP6744150B2 (ja) マイクロ波管、およびマイクロ波管のコレクタ
FR2669771A1 (fr) Cathode amelioree pour tubes hyperfrequence.
FR2775117A1 (fr) Grille pour tube electronique a faisceau axial a performances ameliorees
BE473844A (de)
FR3085991A1 (fr) Element de turbomachine d'aeronef et son procede de controle
FR3066311A1 (fr) Dispositif de centrage d'un ecran metallique dans une ampoule a vide, et ampoule a vide comportant un tel dispositif
BE481085A (de)
FR2613471A1 (fr) Manchon d'etancheite pour echangeur thermique

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210305

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230517

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20240207