US3705319A - Electrodeless gas discharge devices employing tritium as a source of ions to prime the discharge - Google Patents

Electrodeless gas discharge devices employing tritium as a source of ions to prime the discharge Download PDF

Info

Publication number
US3705319A
US3705319A US172847A US3705319DA US3705319A US 3705319 A US3705319 A US 3705319A US 172847 A US172847 A US 172847A US 3705319D A US3705319D A US 3705319DA US 3705319 A US3705319 A US 3705319A
Authority
US
United States
Prior art keywords
discharge device
tritium
capsule
yttrium
titanium
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.)
Expired - Lifetime
Application number
US172847A
Other languages
English (en)
Inventor
Harry Goldie
Michael Goldman
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.)
CBS Corp
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Application granted granted Critical
Publication of US3705319A publication Critical patent/US3705319A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G11/00—Limiting amplitude; Limiting rate of change of amplitude ; Clipping in general
    • H03G11/006—Limiting amplitude; Limiting rate of change of amplitude ; Clipping in general in circuits having distributed constants
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/30—Igniting arrangements
    • H01J17/32—Igniting by associated radioactive materials or fillings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
    • H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
    • H01J65/042—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field
    • H01J65/048—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field the field being produced by using an excitation coil

Definitions

  • ABSTRACT An electrodeless, halogen gas microwave-induced V discharge device, particularly adapted for use as a power limiter stage, which has no wires connected to it.
  • a free electron emitter comprising tritium adsorbed into a layer of material such as titanium or yttrium. The tritium yields sufficient initiatory electrons to prime the microwave gap so as to yield a short interval for radiofrequency breakdown of the gas, and to yield repeatable discharge characteristics with each incident radiofrequency pulse.
  • Such protectors are placed in a wave guide leading from a circulator to the receiverand consist of a quartz or the like capsule containing a halogen gas, preferably chlorine.
  • a halogen gas preferably chlorine.
  • a suitable source of ions or electrons is present to prime the discharge within the gas
  • the capsule isdisposed in an aperture formed in a thin iris plate in the path of wave energy passing through the wave guide
  • a high energy pulse (such as that which would damage the receiver) will ionize the halogen gas.
  • the resulting increase in electron density represents an increase in permittivity of the aperture in the iris plate, changing its capacitance and detuning the circuit. This causes the high energy pulse, which might otherwise damage the receiver, to be reflected.
  • a low energy pulse such as that reflected as an echo from a distant target, will not cause ionization of the halogen gas with the result that the low energy pulse will pass through the iris plate to the receiver, as is intended.
  • a keepalive. stage of the type described above depends for its operation upon ignition of an'electrical gas discharge. Furthermore, the device requires a source of ions-or electrons to prime the discharge, the "performance of the device being beneficially affected by increased availability of priming or initiatory' electrons.
  • a gaseous discharge device which depends for its operation upon a source of priming radiation, and wherein the priming radiation source comprises tritium adsorbed into a layer of material such as titanium or yttrium.
  • the tritium provides only low energy radiation (i.e., electrons) with penetrating power sufficiently small to allow high activities of radiation to be used safely.
  • the gas usually a halogen such as chlorine, is contained within a quartz or the like capsule having a layer of titanium or yttrium with adsorbed tritium on an interior surface thereof.
  • the low energy radiation is introduced into the gas within the capsule through a thin insulating surface such as silica.
  • the invention when incorporated into a multistage radar receiver protector, will yield an all-halogen tube with an extremely fast recovery period and long operating life since in no part of the device does any gas come into contact with a metal surface. Furthermore, the invention enables an assured first pulse breakdown whether the stage has been passive for periods of microseconds or months and reproducible discharge characteristics on a pulseto-pulse basis even though the time between successive pulses is from microseconds to seconds.
  • FIG. 1 is an illustration of the electrical discharge device of the invention as applied to a keepalive stage positioned within a wave guide leading to a radar receiver or the like;
  • H6. 2 is an enlarged cross-sectional view showing the manner in which tritium is adsorbed into a layer of titanium or yttrium on an interior surface of the keepalive stage of FIG. 1;
  • FIG. 3 illustrates a typical application of the gaseous discharge device of the invention.
  • a wave guide section 10 having a thin iris plate or resonant element 12 extending across its width and perpendicular to the axis of the wave guide.
  • the thickness of this element may typically be about mils.
  • an aperture 14 provided at its top and bottom with truncated triangular portions 16 and 18 separated by a gap 20.
  • a hole or bore 22 typically having a diameter of about 50 mils.
  • a halogen gas such as chlorine.
  • the capsule 26 and its communicating, integral capillary 24 are preferably formed from quartz.
  • the upper end wall 28 of the capsule is provided on its undersurface and within the interior of the capsule 26 with a layer of titanium or yttrium having tritium adsorbed therein. With this arrangement, tritium will radiate beta rays (i.e., electrons)v into the halogen gas within the capsule 26 to act as a priming source of electrons to facilitate rapid microwave breakdown of the gas.
  • the details of the capsule 26 and its integral, capillary portion 24 are shown in FIG. 2.
  • the capillary is connected to an upper cup-shaped portion 30, fitted with a cover plate comprising the end wall 28.
  • the capsule is formed from quartz as is the cover plate 28.
  • Deposited on the undersurface of the cover plate 28 by vacuum-deposition techniques is a thin film 32 of titanium or yttrium. This typically has a thickness in the range of about 7,000 to 12,000 Angstrom units.
  • molecular tritium is adsorbed into the film at relatively high temperatures, on the order of 400C.
  • a layer of titanium dioxide or yttrium oxide 34 is formed on the undersurface of the layer 32 by aging in an oxygen atmosphere.
  • a layer of silicon dioxide 36 having a thickness in the range of about 1,000 to 3,000 Angstrom units, is deposited over the metal-oxide surface.
  • the deposition is typically performed by thermal evaporation of silicon monoxide in the vicinity of the metal-oxide surface in a low pressure oxygen ambient of about torr.
  • the silicon dioxide layer 36 is deposited to a thickness which is less than the range of the tritium beta radiation in silica, thereby allowing an appreciable portion of the beta radiation to enter the discharge volume, yet preventing surface desorption and subsequent release of tritium molecules or atoms into the discharge volume.
  • the maximum range of IO KEV beta radiation is 0.2 mg/cm as measured for aluminum adsorbers. This result is applicable to silica. For a range of 0.2 mg/cm in silica, a silica thickness of 8,000 Angstrom units is required to stop the beta radiation. Accordingly, the thickness of the layer 36 must be less than 8,000 Angstrom units.
  • the smaller truncated triangular portion 16 can be either eliminated or increased to the same size as the other truncated portion 18, depending upon the application.
  • the loaded 0 is typically 4 to 7.
  • the ejected betas from the tritium cannot penetrate a surface more than a mil or two thick and, therefore, the device is safe to handle.
  • the silicon dioxide layer 36 acts to prevent any chemical reaction between the tritium host metal and the neutral chlorine. Negligible ionization will occur in the vicinity of the beta emitter, so that sputtering of the silica layer by positive ions will not occur.
  • FIG. 3 A typical use of the device of FIGS. 1 and 2 is shown in FIG. 3.
  • a radar transmitter 38 is connected through a circulator 40 to an antenna 42.
  • the antenna 42 is connected through the same circulator 40 to a dummy load 44 and through a multistage receiver pro tector 46 to a radar receiver 48.
  • the multistage protector 46 includes three stages A, B and C, each of which includes a gaseous discharge device such as that shown in FIGS. 1 and 2.
  • the first stage A is designed to handle megawatts
  • the second stage B is designed to handle tens of watts
  • the third or last stage C is designed to handle milliwatts.
  • Pulses transmitted from the transmitter 38 will have a ma nituge of about I megawatt. Some of this energy may e re ected from the antenna 42 before transmission and have a magnitude of about 8 to kilowatts. These, therefore, will trigger one or more of the gaseous discharge devices within the protector 46 and cause the energy in the range of about 8 to 80 kilowatts to be reflected to the dummy load 44. Echoes from a distant target received by the antenna 42, however, will have a magnitude in the range of about 10 to 10' watts. These will not ionize the gas in the keepalive stages and, consequently, will pass through to the receiver.
  • a capsule In a gaseous discharge device, a capsule, an ionizable gas within said capsule, and a material selected from the group consisting of titanium and yttrium having adsorbed therein tritium providing a source of primary radiation for said discharge device.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Particle Accelerators (AREA)
US172847A 1971-08-18 1971-08-18 Electrodeless gas discharge devices employing tritium as a source of ions to prime the discharge Expired - Lifetime US3705319A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US17284771A 1971-08-18 1971-08-18

Publications (1)

Publication Number Publication Date
US3705319A true US3705319A (en) 1972-12-05

Family

ID=22629478

Family Applications (1)

Application Number Title Priority Date Filing Date
US172847A Expired - Lifetime US3705319A (en) 1971-08-18 1971-08-18 Electrodeless gas discharge devices employing tritium as a source of ions to prime the discharge

Country Status (4)

Country Link
US (1) US3705319A (de)
JP (1) JPS4830347A (de)
DE (1) DE2239802A1 (de)
GB (1) GB1392883A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3858125A (en) * 1972-07-31 1974-12-31 Westinghouse Electric Corp Receiver protection method and apparatus
US4027255A (en) * 1975-10-22 1977-05-31 Westinghouse Electric Corporation Fast recovery time receiver protector for radars
US4063132A (en) * 1976-08-04 1977-12-13 Gte Laboratories Inc. DC powered microwave discharge in an electrodeless light source
US4177437A (en) * 1978-01-20 1979-12-04 The United States Of America As Represented By The Secretary Of The Air Force High power pre-TR switch
US4223250A (en) * 1978-12-22 1980-09-16 Gte Laboratories Incorporated Protective coatings for light sources
US4247800A (en) * 1979-02-02 1981-01-27 Gte Laboratories Incorporated Radioactive starting aids for electrodeless light sources
US4359668A (en) * 1979-03-14 1982-11-16 Fusion Systems Corporation Method and apparatus for igniting electrodeless discharge lamp
US4906898A (en) * 1985-07-05 1990-03-06 Universite De Montreal Surface wave launchers to produce plasma columns and means for producing plasma of different shapes
US4965540A (en) * 1987-12-23 1990-10-23 Hewlett-Packard Company Microwave resonant cavity
US5479174A (en) * 1993-12-06 1995-12-26 Westinghouse Electric Corporation Tritium primed quartz ignitor for radar receiver protector
US6476565B1 (en) * 2001-04-11 2002-11-05 Michael Charles Kaminski Remote powered electrodeless light bulb

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946091A (en) 1972-06-28 1976-03-23 Unitika Limited Aromatic co-polyester articles showing reduced crazing
DE102005043278B4 (de) * 2005-09-09 2011-02-03 Leibniz-Institut für Plasmaforschung und Technologie e.V. Verfahren und Vorrichtung zum Erzeugen eines sich ausdehnenden, diffusen Mikrowellenplasmas

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4531547Y1 (de) * 1968-07-15 1970-12-03

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3858125A (en) * 1972-07-31 1974-12-31 Westinghouse Electric Corp Receiver protection method and apparatus
US4027255A (en) * 1975-10-22 1977-05-31 Westinghouse Electric Corporation Fast recovery time receiver protector for radars
US4063132A (en) * 1976-08-04 1977-12-13 Gte Laboratories Inc. DC powered microwave discharge in an electrodeless light source
US4177437A (en) * 1978-01-20 1979-12-04 The United States Of America As Represented By The Secretary Of The Air Force High power pre-TR switch
US4223250A (en) * 1978-12-22 1980-09-16 Gte Laboratories Incorporated Protective coatings for light sources
US4247800A (en) * 1979-02-02 1981-01-27 Gte Laboratories Incorporated Radioactive starting aids for electrodeless light sources
US4359668A (en) * 1979-03-14 1982-11-16 Fusion Systems Corporation Method and apparatus for igniting electrodeless discharge lamp
US4906898A (en) * 1985-07-05 1990-03-06 Universite De Montreal Surface wave launchers to produce plasma columns and means for producing plasma of different shapes
US4965540A (en) * 1987-12-23 1990-10-23 Hewlett-Packard Company Microwave resonant cavity
US5479174A (en) * 1993-12-06 1995-12-26 Westinghouse Electric Corporation Tritium primed quartz ignitor for radar receiver protector
US6476565B1 (en) * 2001-04-11 2002-11-05 Michael Charles Kaminski Remote powered electrodeless light bulb

Also Published As

Publication number Publication date
JPS4830347A (de) 1973-04-21
DE2239802A1 (de) 1973-02-22
GB1392883A (en) 1975-05-07

Similar Documents

Publication Publication Date Title
US3705319A (en) Electrodeless gas discharge devices employing tritium as a source of ions to prime the discharge
Deb et al. Measurement of lifetime of carriers in semiconductors through microwave reflection
US2557961A (en) Transmission system for highfrequency currents
US2496865A (en) Electronic discharge device
US2643297A (en) Gas discharge transmission arrangement
US2641702A (en) Control of wave length in wave guide and coaxial lines
US2765445A (en) Gas-filled diode discharge tube
US3023380A (en) Microwave switch
US4575692A (en) Microwave discharge apparatus and method with dual function priming resonator
US3644779A (en) Capillary stage for microwave tr devices using static magnetic fields
US2734171A (en) Heins
Patel et al. Microstrip plasma limiter
US2813999A (en) High power r.-f. switch tube
US2703363A (en) Radiation modulating system
US3521197A (en) High frequency power limiter device for a waveguide
US4245197A (en) Radar receiver protector with auxiliary source of electron priming
US2765417A (en) Electric discharge device
US3015822A (en) Ionized-gas beam-shifting tschebyscheff array antenna
US2570893A (en) Electronic attenuator for radar
US3209285A (en) Folded cylinder gaseous discharge device
US2745072A (en) Wave guide gas switching device
US2879485A (en) Broad band electronic switch
US2821658A (en) Arc-limiting shields for high frequency gaseous electric discharge switching tubes
US3534298A (en) Rf energy primed t-r switch
US3147450A (en) Folded cylinder gaseous discharge device