US3274507A - Electron beam plasma amplifier with a wave-guide coupling - Google Patents

Electron beam plasma amplifier with a wave-guide coupling Download PDF

Info

Publication number
US3274507A
US3274507A US164762A US16476262A US3274507A US 3274507 A US3274507 A US 3274507A US 164762 A US164762 A US 164762A US 16476262 A US16476262 A US 16476262A US 3274507 A US3274507 A US 3274507A
Authority
US
United States
Prior art keywords
plasma
electron beam
signal
coupling means
frequency
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
US164762A
Inventor
Weimer Karl Richard Ulrich
Vlaardingerbroek Marinu Teunis
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.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips 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 US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3274507A publication Critical patent/US3274507A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/04—Electrodes; Screens
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/005—Gas-filled transit-time tubes

Definitions

  • the invention relates to a sign-a1 amplifying device comprising an electron beam tube, in which the signal to be amplified is fed to an input coupler and the amplified signal is derived from an output coupler, farther remote from the electron gun and in which the signal is amplified by the interaction of the electron beam with a plasma having a plasma frequency which is at least equal to the signal frequency.
  • a sign-a1 amplifying device comprising an electron beam tube, in which the signal to be amplified is fed to an input coupler and the amplified signal is derived from an output coupler, farther remote from the electron gun and in which the signal is amplified by the interaction of the electron beam with a plasma having a plasma frequency which is at least equal to the signal frequency.
  • a plasma having a plasma frequency which is at least equal to the signal frequency.
  • a modulated beam is guided across the plasma whereas input and output coupling take place beyond the interaction space of the electron beam and the plasma on the beam.
  • the electron beam is modulated in the conventional manner with the signal, in the manner described in the said device, for example with the aid of helices. In order to obtain the desired couplings these helices may sometimes require great dimensions.
  • high frequency signals for example of more than 10,000 mc./s.
  • the couplers can be constructed only with difiiculty.
  • the length of the electron beam, owing to the couplers must be considerably greater than the interaction space of the beam and the plasma.
  • the invention obviates these disadvantages by providing a particular embodiment of the couplers. It is based on the recognition of the fact that within the interaction space of the beam and the plasma provision is made not only of a modulated beam and a plasma, but also of a modulated beam and a modulated plasma. It is hence possible to carry out the coupling operation in the plasma space. This means that, if by some means the plasma is set oscillating the device can also provide an amplification of the signal.
  • At least one of the signal couplers is located in the range of the plasma while the coupler is constructed in the form of a coupler suitable for use in a waveguide system.
  • This arrangement has the advantage that coupling can be obtained in a simple manner, since it is not bound to the shape characteristic of an electron beam, while the length may be shorter.
  • the construction in the form of a coupler suit-able for use with a waveguide system may be obtained by means of a loop, a coupling hole or an antenna.
  • At least one of the signal couplers is particularly located in the interaction range of the electron beam and the plasma since this provides an improved signal transfer.
  • the invention furthermore relates to an electron beam tube comprising a coupler for supplying the signal to be amplified, an output coupler farther remote from the electron gun for deriving the amplified signal and means for producing a plasma by the interaction of which with the electron beam signal amplification is obtained, in
  • At least one of the signal couplers is located in the range of the plasma while the coupler is constructed in the form of a coupler suitable for use in a waveguide system. At least one of the signal couplers is located particularly in the interaction space of the electron beam and the plasma.
  • the electron beam is produced in the conventional manner by an electron gun and an anode located behind the former, while the beam may strike a collector at the end of the tube.
  • a collector may be dispensed with, since the beam may terminate owing to collisions of beam electrons with the plasma particles.
  • the output coupler may be arranged beyond the interaction space of the beam and the plasma.
  • a plasma is to be understood to denote herein a mixture of positively and negatively charged particles, which can be produced between a cathode, which may be a heating cathode, and an anode.
  • the electrons in the plasma perform an oscillatory motion, of which the frequency, the so-called plasma frequency, depends upon the electron density in the plasma.
  • FIG. 1 shows diagrammaticaly an electron beam tube
  • FIG. 2 shows diagrammatically a different embodiment of such an electron beam tube.
  • the electron beam tube shown in a diagrammatical sectional view in FIG. 1 comprises a gun I and an anode 2 for producing the electron beam.
  • This beam anode 2 serves, moreover, as a plasma anode.
  • the plasma is produced between this plasma anode and the plasma cathode 3 in the glass bulb 4.
  • Through the glass wall are taken the input coupler 5 and the output coupler 6.
  • These couplers are shaped in the form of a loop.
  • To the input coupler 5 is fed the signal to be amplified from a device which is not shown, whereas the amplified signal is fed by the output coupler 6 to a further device not shown.
  • the plasma cathode 3, which is shaped in the form of heating cathode, serves moreover as a beam collector.
  • the plasma is obtained by a mercury vapour discharge at a pressure of 2X l0 torr, a discharge current across the plasma of ma. and a voltage between the plasma cathode and the plasma anode, the so-called burning voltage of the plasma of 20 v.
  • the electron density in the plasma amounts to about 2x 10 cm. This density corresponds to a plasma frequency of about 4000 mc./s. With this adjustment the tube is therefore suitable for amplifying signals having a frequency of not more than 4000 mc./s. with which signal frequency the maximum amplification is obtained.
  • the voltage between the cathode and the anode in the beam is 300 v., whereas the beam current amounts to 2 ma. When the beam enters the interaction space, it has a diameter of 2 mms.
  • the electron beam tube shown diagrammatically in FIG. 2 comprises a gun 11 and an anode 12 for producing an electron beam.
  • This beam anode 12 serves, moreover, as a plasma cathode.
  • the plasma is produced between this plasma oathode and the plasma anode 13 in the glass bulb 14.
  • the input coupler is shaped in the form of a coupling hole 15 and the output coupler is shaped in the form of an antenna 16.
  • the signal supply device and the signal output device connected herewith are not shown.
  • the plasma anode 13 serves, in addition, as a beam collector, if the beam has not yet been annulled by collision with plasma particles.
  • An electron beam plasma amplifier comprising an envelope containing an ionizable gaseous medium, means within said envelope for generating an electron beam, first and second electrodes directly in the path of the electron beam defining a plasma discharge space and for generating a plasma, coupling means for introducing an input signal of given frequency directly into said plasma discharge space, said plasma having a plasma frequency which is at least equal to the signal frequency, the signal being amplified by interaction between the electron beam and the plasma, and output coupling means for extnacting an amplified signal from said plasma discharge space, said output coupling means being positioned more remote from said electron beam generating means than said input coupling means, at least one of said coupling means being a wave-guide coupler and being positioned in the plasma discharge space.
  • An electron beam plasma amplifier comprising an envelope containing an ionizable gaseous medium, an electron gun within said envelope for generating an electron beam, said electron gun comprising a cathode and an apertured anode for the passage of the electron beam, a second cathode spaced from and operatively associated with said anode and defining a plasma discharge space in which plasma is produced from said ionizable medium, coupling means between said anode and said second cathode for introducing an input signal of given frequency into said plasma discharge space, said plasma having a plasma frequency which is at least equal to the signal frequency, the signal being amplified by interaction between the electron beam and the plasma, and output coupling means for extracting an amplified signal from said plasma discharge space, said output coupling means being positioned more remote from said anode than said input coupling means, at least one of said coupling means being a wave-guide coupler and being positioned in the plasma discharge space.
  • An electron beam plasma amplifier comprising an envelope containing an ionizable gaseous medium, an electron gun within said envelope for generating an electron beam, said electron gun comprising a cathode and an apertured anode for the passage of an electron beam, a second cathode spaced from and operatively associated with said anode and defining a plasma discharge space in which plasma is produced from said ionizable medium, coupling means between said anode and said second cathode for introducing an input signal of given frequency into said plasma discharge space, said plasma having a plasma frequency which is at least equal to the signal frequency, the signal being amplified by interaction between the electron beam and the plasma, and output coupling means for extracting an amplified signal from said plasma discharge space, said output coupling means being positioned more remote from said anode than said input coupling means, at least one of said coupling means being a wave-guide coupler and being positioned in the interaction region of the electron beam and the plasma.

Description

Sept. 20, 1966 K. R. u. WEIMER ETAL 3,274,507
ELECTRON BEAM PLASMA AMPLIFIER WITH A WAVE-GUIDE COUPLING Filed Jan. 8, 1962 INVENTOR V kart Ruwelmer Marinus T. Vlaardmgerbroek United States Patent 3,274,507 ELECTRON BEAM PLASMA AMPLIFIER WITH A WAVE-GUIDE COUPLING Karl Richard Ulrich Weimer and Marinas Tennis Vlaardingerbroek, Emrnasingel, Eindhoven, Netherlands, assignors to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware Filed Jan. 8, 1962, Ser. No. 164,762 Claims priority, application Netherlands, Jan. 13, 1961, 260,047 3 Claims. (Cl. 330-41) The invention relates to a sign-a1 amplifying device comprising an electron beam tube, in which the signal to be amplified is fed to an input coupler and the amplified signal is derived from an output coupler, farther remote from the electron gun and in which the signal is amplified by the interaction of the electron beam with a plasma having a plasma frequency which is at least equal to the signal frequency. Such a device is described in Physical Review, vol. 109, No. 4, pages 1393-1394 (1958). In this case the electron beam is modulated with the aid of a short helix with the signal to be amplified and then guided along the axis of the positive column of a mercury vapour discharge. Beyond the interaction space of plasma and beam the electron beam is coupled by means of "a second helix with an output coupler, so that an amplified signal is obtained.
With the known device a modulated beam is guided across the plasma whereas input and output coupling take place beyond the interaction space of the electron beam and the plasma on the beam. The electron beam is modulated in the conventional manner with the signal, in the manner described in the said device, for example with the aid of helices. In order to obtain the desired couplings these helices may sometimes require great dimensions. When using high frequency signals, for example of more than 10,000 mc./s. there is the disadvantage that the couplers can be constructed only with difiiculty. Moreover, to each frequency it applies that the length of the electron beam, owing to the couplers, must be considerably greater than the interaction space of the beam and the plasma.
The invention obviates these disadvantages by providing a particular embodiment of the couplers. It is based on the recognition of the fact that within the interaction space of the beam and the plasma provision is made not only of a modulated beam and a plasma, but also of a modulated beam and a modulated plasma. It is hence possible to carry out the coupling operation in the plasma space. This means that, if by some means the plasma is set oscillating the device can also provide an amplification of the signal.
In accordance with the invention at least one of the signal couplers is located in the range of the plasma while the coupler is constructed in the form of a coupler suitable for use in a waveguide system. This arrangement has the advantage that coupling can be obtained in a simple manner, since it is not bound to the shape characteristic of an electron beam, while the length may be shorter. The construction in the form of a coupler suit-able for use with a waveguide system may be obtained by means of a loop, a coupling hole or an antenna.
At least one of the signal couplers is particularly located in the interaction range of the electron beam and the plasma since this provides an improved signal transfer.
The invention furthermore relates to an electron beam tube comprising a coupler for supplying the signal to be amplified, an output coupler farther remote from the electron gun for deriving the amplified signal and means for producing a plasma by the interaction of which with the electron beam signal amplification is obtained, in
"ice
which at least one of the signal couplers is located in the range of the plasma while the coupler is constructed in the form of a coupler suitable for use in a waveguide system. At least one of the signal couplers is located particularly in the interaction space of the electron beam and the plasma.
The electron beam is produced in the conventional manner by an electron gun and an anode located behind the former, while the beam may strike a collector at the end of the tube. In the device according to the invention a collector may be dispensed with, since the beam may terminate owing to collisions of beam electrons with the plasma particles. Since in accordance with the invention the coupling is performed with the plasma the output coupler may be arranged beyond the interaction space of the beam and the plasma. A plasma is to be understood to denote herein a mixture of positively and negatively charged particles, which can be produced between a cathode, which may be a heating cathode, and an anode. The electrons in the plasma perform an oscillatory motion, of which the frequency, the so-called plasma frequency, depends upon the electron density in the plasma.
The invention will now be described more fully with reference to the drawings, in which FIG. 1 shows diagrammaticaly an electron beam tube and FIG. 2 shows diagrammatically a different embodiment of such an electron beam tube.
The electron beam tube shown in a diagrammatical sectional view in FIG. 1 comprises a gun I and an anode 2 for producing the electron beam. This beam anode 2 serves, moreover, as a plasma anode. The plasma is produced between this plasma anode and the plasma cathode 3 in the glass bulb 4. Through the glass wall are taken the input coupler 5 and the output coupler 6. These couplers are shaped in the form of a loop. To the input coupler 5 is fed the signal to be amplified from a device which is not shown, whereas the amplified signal is fed by the output coupler 6 to a further device not shown. The plasma cathode 3, which is shaped in the form of heating cathode, serves moreover as a beam collector.
In a given construction of this tube the plasma is obtained by a mercury vapour discharge at a pressure of 2X l0 torr, a discharge current across the plasma of ma. and a voltage between the plasma cathode and the plasma anode, the so-called burning voltage of the plasma of 20 v. The electron density in the plasma amounts to about 2x 10 cm. This density corresponds to a plasma frequency of about 4000 mc./s. With this adjustment the tube is therefore suitable for amplifying signals having a frequency of not more than 4000 mc./s. with which signal frequency the maximum amplification is obtained. The voltage between the cathode and the anode in the beam is 300 v., whereas the beam current amounts to 2 ma. When the beam enters the interaction space, it has a diameter of 2 mms.
The electron beam tube shown diagrammatically in FIG. 2 comprises a gun 11 and an anode 12 for producing an electron beam. This beam anode 12 serves, moreover, as a plasma cathode. The plasma is produced between this plasma oathode and the plasma anode 13 in the glass bulb 14. The input coupler is shaped in the form of a coupling hole 15 and the output coupler is shaped in the form of an antenna 16. The signal supply device and the signal output device connected herewith are not shown. The plasma anode 13 serves, in addition, as a beam collector, if the beam has not yet been annulled by collision with plasma particles.
What is claimed is:
1. An electron beam plasma amplifier comprising an envelope containing an ionizable gaseous medium, means within said envelope for generating an electron beam, first and second electrodes directly in the path of the electron beam defining a plasma discharge space and for generating a plasma, coupling means for introducing an input signal of given frequency directly into said plasma discharge space, said plasma having a plasma frequency which is at least equal to the signal frequency, the signal being amplified by interaction between the electron beam and the plasma, and output coupling means for extnacting an amplified signal from said plasma discharge space, said output coupling means being positioned more remote from said electron beam generating means than said input coupling means, at least one of said coupling means being a wave-guide coupler and being positioned in the plasma discharge space.
2. An electron beam plasma amplifier comprising an envelope containing an ionizable gaseous medium, an electron gun within said envelope for generating an electron beam, said electron gun comprising a cathode and an apertured anode for the passage of the electron beam, a second cathode spaced from and operatively associated with said anode and defining a plasma discharge space in which plasma is produced from said ionizable medium, coupling means between said anode and said second cathode for introducing an input signal of given frequency into said plasma discharge space, said plasma having a plasma frequency which is at least equal to the signal frequency, the signal being amplified by interaction between the electron beam and the plasma, and output coupling means for extracting an amplified signal from said plasma discharge space, said output coupling means being positioned more remote from said anode than said input coupling means, at least one of said coupling means being a wave-guide coupler and being positioned in the plasma discharge space.
3. An electron beam plasma amplifier comprising an envelope containing an ionizable gaseous medium, an electron gun within said envelope for generating an electron beam, said electron gun comprising a cathode and an apertured anode for the passage of an electron beam, a second cathode spaced from and operatively associated with said anode and defining a plasma discharge space in which plasma is produced from said ionizable medium, coupling means between said anode and said second cathode for introducing an input signal of given frequency into said plasma discharge space, said plasma having a plasma frequency which is at least equal to the signal frequency, the signal being amplified by interaction between the electron beam and the plasma, and output coupling means for extracting an amplified signal from said plasma discharge space, said output coupling means being positioned more remote from said anode than said input coupling means, at least one of said coupling means being a wave-guide coupler and being positioned in the interaction region of the electron beam and the plasma.
References Cited by the Examiner UNITED STATES PATENTS 1,984,499 12/1934 St. Laurent 33041 X 2,750,455 6/1956 Geisler 33041 X 2,806,974 9/1957 Haeff a 315-3.6 2,817,045 12/1957 Goldstein 31539 2,848,649 8/1958 Bryant 31539 3,099,768 7/ 1963 Anderson.
3,111,604 11/1963 Agdur 33041 .JAMES W. LAWRENCE, Primary Examiner.
GEORGE N. WESTBY, DAVID J. GALVIN,
Examiners.
V. LAFRANCHI, S. SCHLOSSER, R. SEGAL,
Assistant Examiners.

Claims (1)

1. AN ELECTRON BEAM PLASMA AMPLIFIER COMPRISING AN ENVELOPE CONTAINING AN IONIZABLE GASEOUS MEDIUM, MEANS WITHIN SAID ENVELOPE FOR GENERATING AN ELECTRON BEAM, FIRST AND SECOND ELECTRODES DIRETLY IN THE PATH OF THE ELECTRON BEAM DEFINING A PLASMA DISCHARGE SPACE AND FOR GENERATING A PLASMA, COUPLING MEANS FOR INTRODUCING AN INPUT SIGNAL OF GIVEN FREQUENCY DIRECTLY INTO SAID PLASMA DISCHARGE SPACE, SAID PLASMA HAVING A PLASMA FREQUENCY WHICH IS AT LEAST EQUAL TO THE SIGNAL FREQUENCY, THE SIGNAL BEING AMPLIFIED BY INTERACTION BETWEEN THE ELECTRON BEAM AND THE PLASMA, AND OUTPUT COUPLING MEANS FOR EXTRACTING AN AMPLIFIED SIGNAL FROM SAID PLASMA DISCHARGE SPACE, SAID OUTPUT COUPLING MEANS BEING POSITIONED MORE REMOTE FROM SAID ELECTRON BEAM GENERATING MEAN THAN SAID INPUT COUPLING MEANS, AT LEAST ONE OF SAID COUPLING MEANS BEING A WAVE-GUIDE COUPLER AND BEING POSITIONED IN THE PLASMA DISCHARGE SPACE.
US164762A 1961-01-13 1962-01-08 Electron beam plasma amplifier with a wave-guide coupling Expired - Lifetime US3274507A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL260047 1961-01-13

Publications (1)

Publication Number Publication Date
US3274507A true US3274507A (en) 1966-09-20

Family

ID=19752810

Family Applications (1)

Application Number Title Priority Date Filing Date
US164762A Expired - Lifetime US3274507A (en) 1961-01-13 1962-01-08 Electron beam plasma amplifier with a wave-guide coupling

Country Status (3)

Country Link
US (1) US3274507A (en)
GB (1) GB959421A (en)
NL (1) NL260047A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3363138A (en) * 1964-11-04 1968-01-09 Sperry Rand Corp Electron beam-plasma device operating at multiple harmonics of beam cyclotron frequency
US3378712A (en) * 1966-11-18 1968-04-16 Gen Electric Field emission ionization gauge with restricted line of sight between field emissionanode and ion collector
US3423694A (en) * 1964-08-26 1969-01-21 Melpar Inc Radiant energy source
US3432721A (en) * 1966-01-17 1969-03-11 Gen Electric Beam plasma high frequency wave generating system
US3432722A (en) * 1966-01-17 1969-03-11 Gen Electric Electromagnetic wave generating and translating apparatus
WO1989010000A1 (en) * 1988-04-14 1989-10-19 Hughes Aircraft Co Plasma-assisted high-power microwave generator
US4916361A (en) * 1988-04-14 1990-04-10 Hughes Aircraft Company Plasma wave tube

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1984499A (en) * 1932-09-14 1934-12-18 Radio Res Lab Inc Coupling system and apparatus
US2750455A (en) * 1953-05-28 1956-06-12 Ibm Radio frequency controlled plasmatron
US2806974A (en) * 1954-07-06 1957-09-17 Hughes Aircraft Co Plasma amplifiers
US2817045A (en) * 1952-02-05 1957-12-17 Itt Electromagnetic wave generator
US2848649A (en) * 1952-01-24 1958-08-19 Itt Electromagnetic wave generator
US3099768A (en) * 1959-03-25 1963-07-30 Gen Electric Low noise electron beam plasma amplifier
US3111604A (en) * 1960-06-13 1963-11-19 Ericsson Telefon Ab L M Electronic device for generating or amplifying high frequency oscillations

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1984499A (en) * 1932-09-14 1934-12-18 Radio Res Lab Inc Coupling system and apparatus
US2848649A (en) * 1952-01-24 1958-08-19 Itt Electromagnetic wave generator
US2817045A (en) * 1952-02-05 1957-12-17 Itt Electromagnetic wave generator
US2750455A (en) * 1953-05-28 1956-06-12 Ibm Radio frequency controlled plasmatron
US2806974A (en) * 1954-07-06 1957-09-17 Hughes Aircraft Co Plasma amplifiers
US3099768A (en) * 1959-03-25 1963-07-30 Gen Electric Low noise electron beam plasma amplifier
US3111604A (en) * 1960-06-13 1963-11-19 Ericsson Telefon Ab L M Electronic device for generating or amplifying high frequency oscillations

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3423694A (en) * 1964-08-26 1969-01-21 Melpar Inc Radiant energy source
US3363138A (en) * 1964-11-04 1968-01-09 Sperry Rand Corp Electron beam-plasma device operating at multiple harmonics of beam cyclotron frequency
US3432721A (en) * 1966-01-17 1969-03-11 Gen Electric Beam plasma high frequency wave generating system
US3432722A (en) * 1966-01-17 1969-03-11 Gen Electric Electromagnetic wave generating and translating apparatus
US3378712A (en) * 1966-11-18 1968-04-16 Gen Electric Field emission ionization gauge with restricted line of sight between field emissionanode and ion collector
WO1989010000A1 (en) * 1988-04-14 1989-10-19 Hughes Aircraft Co Plasma-assisted high-power microwave generator
US4916361A (en) * 1988-04-14 1990-04-10 Hughes Aircraft Company Plasma wave tube

Also Published As

Publication number Publication date
NL260047A (en)
GB959421A (en) 1964-06-03

Similar Documents

Publication Publication Date Title
US3558967A (en) Linear beam tube with plural cathode beamlets providing a convergent electron stream
US3432721A (en) Beam plasma high frequency wave generating system
US2416303A (en) Secondary emissive shell resonator tube
US2848649A (en) Electromagnetic wave generator
US3274507A (en) Electron beam plasma amplifier with a wave-guide coupling
GB1039833A (en) Crossed field tube
US2852715A (en) High frequency structure
US3378723A (en) Fast wave transmission line coupled to a plasma
US3432722A (en) Electromagnetic wave generating and translating apparatus
US2289906A (en) Cathode ray tube
US3317784A (en) Travelling wave tube using a plasmafilled waveguide as a slow wave structure
US2757311A (en) Double beam progressive wave tube
US2073599A (en) Electric discharge device
US3483419A (en) Velocity modulation tube with r.f. lossy leads to the beam focusing lenses
US3201640A (en) Electron gun in the form of a multipactor
US2228276A (en) Electrical gaseous discharge device
US3433992A (en) O-type traveling wave tube amplifier having means for counteracting the modulation of the spent beam in the collector electrode region
US2936393A (en) Low noise traveling-wave tube
US2323560A (en) Electron discharge apparatus
US2842703A (en) Electron gun for beam-type tubes
US3388281A (en) Electron beam tube having a collector electrode insulatively supported by a cooling chamber
US2845567A (en) Indirectly heated thermionic cathode
US3688152A (en) High power klystron
US3214632A (en) Low noise electron gun
GB691900A (en) Electron discharge devices