US2183309A - Electron multiplier - Google Patents

Electron multiplier Download PDF

Info

Publication number
US2183309A
US2183309A US196496A US19649638A US2183309A US 2183309 A US2183309 A US 2183309A US 196496 A US196496 A US 196496A US 19649638 A US19649638 A US 19649638A US 2183309 A US2183309 A US 2183309A
Authority
US
United States
Prior art keywords
electron
aperture
diaphragm
stream
image
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
US196496A
Other languages
English (en)
Inventor
Fiechaig Werner
Behne Rudolf
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.)
FIRM OF FERNSEH AKTIEN GES
FIRM OF FERNSEH AKTIEN-GESELLSCHAFT
Original Assignee
FIRM OF FERNSEH AKTIEN GES
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 FIRM OF FERNSEH AKTIEN GES filed Critical FIRM OF FERNSEH AKTIEN GES
Application granted granted Critical
Publication of US2183309A publication Critical patent/US2183309A/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
    • H01J43/00—Secondary-emission tubes; Electron-multiplier tubes
    • H01J43/04—Electron multipliers
    • H01J43/06—Electrode arrangements
    • H01J43/08—Cathode arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J43/00—Secondary-emission tubes; Electron-multiplier tubes
    • H01J43/04—Electron multipliers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49826—Assembling or joining
    • Y10T29/49861—Sizing mating parts during final positional association

Definitions

  • This invention relates .to electron. multipliers and particularly to multipliers in which the number of primary electrons is varied in accordance with a signal.
  • Tubes have been constructed hitherto in which a beam of primary electrons of defined. cross section is deflected across an aperture of aidiaphragm or across a boundary 'of a-diaphragm,
  • an electron image of a clearly-defined cross section of an electron beam is produced by means of electrostatic lenses and this-electron image is deflected by means of a deflecting system, over a l boundary located in the plane of the electron image.
  • the clearly-defined cross section of the electron beam can be gained by means of a suitable aperture in a diaphragmagainst which the' initial stream of electrons isdirected.
  • Another i possibility is that the smallest cross section of the electron beam in front of. the cathode, i. e., the first cross-over, is used for electron-optical reproduction. It suflices even that the reproduced cross section is clearly defined andpossesses sharp outlines on one side only. Gener- I ally a uniform intensity of the portion of the reproduced cross section used-for intensity controlis desirable. 4 e
  • Anelectron image of a cross sectionof an electron beam of substantiallyuniform electron density is produced by means of cylindrical electrodes forming an electron optical lens system.
  • the undeflected position of this electron image lies in close proximity to an aperture in a diaphragm .disposedin the plane of the electron image.
  • the electron image is deflected across the aperture, thereby varying the amount of elec- -in the trons passingthrough the aperture into an electron multiplier.
  • the amplitudes of the deflecting voltage which is simultaneouslythecontrol .voltage, are chosen to be so'small that only a smalljportion of the electronimage is deflected 5 over-the aperture?
  • the amplitude of deflection plane of the'electron image may be, for instance, only 1/100 mm,
  • an electrostatic lens for the develop ment of the electron image is preferable because of the lack of current flow therein which increases the simplicity in filtering means over magnetic lenses.
  • a shield against extraneous magnetic 'fields must be provided.
  • an iron shield which may in part consist of windings of iron wire and which is subjected to an annealing process.
  • an electrostatic lens 2 system since the placing of amagnetic electron optical system inside the iron shield would have considerabledisadvantages.
  • the combination of a screen against extraneous magnetic fields and an electrostatic lens system highest sensitivity obtainable.
  • FIG. 1 is a viewin section longitudinally of the tube.
  • Fig. 2 is a view in section along the linear-2 of Fig. 1.
  • Fig. 3 is a view of Fig.- 1. I I I
  • Fig. 1 shows a vacuum recepin section along the line 3-3 tacle I housing a cathode 2, which is preferably indirectly heated and held at a comparatively low temperature.
  • this cathode is an elongated oxide cathode with its axis normal to the axis of the tube.
  • Two plates, 3 and l, are disposed on the sides of the cathode, which plates replace the conventional concentrating cylinder. In this arrangement a separate-lead from eachof the plates 3 and l is brought out so that different direct current 120- tentials may be applied to them. In this manner, it is possible to focus theemission from the cathode upon an aperture in a diaphragm 5.
  • the aperture in the diaphragm S possesses the shape of an elongated rectangle, and is so small that the electron den-- sity of the electron beam passing through it is substantially uniform.
  • a screeningelectrode 6 is disposed, possessing a larger aperture, which .alone renders the 25- is held at the same potential as the diaphragm 5 and a cylindrical electrode I. This prevents the field between the diaphragm 5 and the oathode 2 from reaching through the aperture of 5 the diaphragm 5 and, thereby, distorting the electron image.
  • the electron-optical system consists of a series of three cylinders, I, 8 and 9, which are provided with annular discs at their ends. These 10 cylinders are aligned along the tube axis and are so dimensioned that the magnification factor with which the electron image is created in the plane I0 is approximately unity, or smaller.
  • the space between the electrodes 9 and I0 is taken up by deflection fields generated by potentials applied to the deflecting plates II and i2.
  • potential applied to electrodes 9 and I0 may be approximately 1,000 volts positive with respect to the cathode. Because of the very weak defleeting voltages (smaller than one millivolt), it
  • the interior of the vacuum receptacle with an electrostatic screen for prevention of wall charges.
  • This screen can be omitted in the adjacent multiplier structure.
  • the size of the aperture in electrode I0 is accurately matched to the electron image of the aperture in the diaphragm 5, which is produced in the plane of electrode [0. It is, how- ,ever, preferable to make this aperture as narrow as possible because it is then possible to prevent interfering electrons from entering the multiplying chamber.
  • the long side of the aperture in electrode I0 can be made smaller than the long side of the aperture in the diaphragm 5.
  • the electrode l3 nearer the cathode is held at apotential of 980 volts, whereas the electrode ll is held at a potential of only 50 volts.
  • the electrode l3 prevents secondary electrons which are liberated from the electrode l0 by unutilized portions of the electron beam from passing through the aperture in the electrode I0.
  • Electrode l4 prevents the passage of secondary electrons into the multiplying chamber which are liberated from the electrode 5 and pass through its aperture into the deflecting space. Ifthe electrode 5 is held at a potential of '70 volts, secondary electrons liberated therefrom are so highly decelerated in the plane of the disc I4 that their passage into the multiplying chamber is prevented.
  • the electrode M can simultaneously be used ing it with high frequency currents. Contrary to conventional practice in cathode ray tubes, the distance between the deas the first secondary emitting electrode of the multiplier system by covering its opening with a wire meshwork capable of secondary emission. The impacting velocity of the electrons emitted by .the cathode and passing through the aperture in the electrode I0 is approximately 50 volts and is sufficient for secondary emission at a ratio greater than unity. Any known type of electron multiplier can be located behind electrode M. In the present case, a number of secondarily emissive grids 18 are shown in back of which a collector plate I! is disposed.
  • the diaphagm I0 is preferably so mounted that it can be moved or rotated in order to align it to the exact position of the electron image.
  • it may be held by a drop of metal of low melting point (for instance, lead or tin) which is held in a smaller receptacle l5. If necessary, this metal drop can be melted by heat-
  • the position of the diaphragm can then be adjusted in vacuo by means of the force of gravity. It is then held in the new position by the congealed metal.
  • the remaining electrodes can be fixed upon glass rods 16 and I1. It is necessary that all electrodes consist of completely non-magnetic material.
  • Electron multiplier comprising means for generating a primary electron stream, means for producing an electron image of a defined cross section of said electron stream in a plane, 9. diaphragm in said plane possessing an aperture having dimensions substantially proportional to the cross-sectional dimensions of said beam image and an area approximately equal to said beam image, means for deflecting said electron image across said aperture, means for amplifying by electron multiplication that portion of said electron stream passing through said aper ture, and means for collecting the amplified porand means for collecting the amplified portion of 1 said electron stream.
  • Electron multiplier comprising an elongated oxide cathode for generating a primary electron stream, a diaphragm in front of said cathode possessing a rectangular aperture, the axis of said cathode being parallel to the longitudinal axis of said rectangular aperture, means for producing an electron image of the cross section of said electron stream passing through said rectangular aperture, in a plane, a second diaphragm in said plane possessing an aperture, means for deflecting said electron image across said last-named aperture, means for amplifying by electron mul-- I tiplication that portion of said electron stream' passing through said last-named aperture, and
  • Electron multiplier comprising means for generating a primary electron stream, means for producing an electron image of a defined cross section of said electron stream in a plane, a dia-.
  • Electron multiplier comprising means forgenerating a primary stream of electrons, means for selecting a cross section of said electron stream, said means comprising a diaphragm possessing an aperture and means for producing a substantially equipotential space about said aperture, means for producing an electron image of said cross section in a plane, a second diaphragm in said plane possessing an aperture, means for deflecting said electron image across said lastnamed aperture, means for amplifying by electron multiplication that portion of the electron stream passing through said last-named aperture, and means for collecting the amplified portion of said electron stream.
  • Electron multiplier comprising means for generating a primary stream of electrons, concentrating means comprising a plurality of electrodes positioned about said electron generating means, means for selecting a cross section of said electron stream, means for producing an electron image of a defined cross section 01' said electron stream in a plane, a diaphragm in said plane possessing an aperture, means for deflecting said electron image across said laperture, means for amplifying by electron multiplication that portion of said electron stream passing through said aperture, and means for collectingthe amplified portion of said electron stream.
  • Electron multiplier comprising means for generating a primary electron stream, means for selecting a defined cross-sectional portion of said electron stream and producing an electron image of said defined cross sectional portion in a plane,
  • a diaphragm in said plane possessing an aperture having an area of the order of said defined cross- ,sectional portion, means for deflecting said electron image across said aperture, means for aniplifying by electron multiplication that portion of said electron streampassing through said aperture, and means for collecting the amplifiedportion of said electron stream.
  • Electron multiplier comprising means for generating a primary electron stream, means for producing an electron image of a defined cross section of said electron stream in a plane, a diaphragm in said plane possessing an aperture, means for deflecting said electron image across said'aperture, means for amplifying by electron multiplication that portion of said electron stream passing through said aperture, means-located between said apertured diaphragm and said electron multiplying means for preventing undesirable secondary electrons from entering the multiplication chamber, and means for collecting the amplified portion of said electron stream.
  • Electron multiplier as set forth in claim 1, possessing an electrostatic shield for prevention of wall charge.
  • the method of electron multiplication comprising the steps of generating a primary stream of electrons, selecting-a cross section of said stream of uniform electron density, pro- .ducing an electron image of saidportion of said cross section, deflecting said electron image over a distance equal to a fraction of its size across an aperture disposed in said plane, subjecting the electrons passing through said aperture to multiplication by secondary emission, and collecting the multiplied electron stream.

Landscapes

  • Electron Sources, Ion Sources (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
US196496A 1937-03-19 1938-03-17 Electron multiplier Expired - Lifetime US2183309A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE835462X 1937-03-19
DE493751X 1937-04-08

Publications (1)

Publication Number Publication Date
US2183309A true US2183309A (en) 1939-12-12

Family

ID=34105296

Family Applications (1)

Application Number Title Priority Date Filing Date
US196496A Expired - Lifetime US2183309A (en) 1937-03-19 1938-03-17 Electron multiplier

Country Status (4)

Country Link
US (1) US2183309A (de)
AT (1) AT160907B (de)
FR (1) FR835462A (de)
GB (1) GB493751A (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2439504A (en) * 1944-03-09 1948-04-13 Emi Ltd Flat beam cathode-ray tube and circuit
US2452620A (en) * 1946-11-14 1948-11-02 Rca Corp Electrode support in television tubes
US2460381A (en) * 1946-02-07 1949-02-01 Rca Corp Multiplier unit and supporting means
US2462496A (en) * 1942-04-24 1949-02-22 Rca Corp Electron discharge device
US2520152A (en) * 1943-11-18 1950-08-29 Farnsworth Res Corp Radiant energy receiving device
US2701320A (en) * 1950-05-26 1955-02-01 Rca Corp Electron gun structure and method for making the same
US2846607A (en) * 1956-09-20 1958-08-05 Thomas Electronics Inc Electron gun
US2943227A (en) * 1956-07-06 1960-06-28 Itt Electron gun support
US2947897A (en) * 1958-01-08 1960-08-02 Itt Electron gun structure
US3004183A (en) * 1957-12-03 1961-10-10 Itt Electron gun
US3047759A (en) * 1959-03-30 1962-07-31 Gen Dynamics Corp Cathode-ray tube structure
US3066235A (en) * 1959-11-12 1962-11-27 Gen Dynamics Corp Means for influencing selectively the cross section and the horizontal and vertical position of a cathode ray electron beam

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2462496A (en) * 1942-04-24 1949-02-22 Rca Corp Electron discharge device
US2520152A (en) * 1943-11-18 1950-08-29 Farnsworth Res Corp Radiant energy receiving device
US2439504A (en) * 1944-03-09 1948-04-13 Emi Ltd Flat beam cathode-ray tube and circuit
US2460381A (en) * 1946-02-07 1949-02-01 Rca Corp Multiplier unit and supporting means
US2452620A (en) * 1946-11-14 1948-11-02 Rca Corp Electrode support in television tubes
US2701320A (en) * 1950-05-26 1955-02-01 Rca Corp Electron gun structure and method for making the same
US2943227A (en) * 1956-07-06 1960-06-28 Itt Electron gun support
US2846607A (en) * 1956-09-20 1958-08-05 Thomas Electronics Inc Electron gun
US3004183A (en) * 1957-12-03 1961-10-10 Itt Electron gun
US2947897A (en) * 1958-01-08 1960-08-02 Itt Electron gun structure
US3047759A (en) * 1959-03-30 1962-07-31 Gen Dynamics Corp Cathode-ray tube structure
US3066235A (en) * 1959-11-12 1962-11-27 Gen Dynamics Corp Means for influencing selectively the cross section and the horizontal and vertical position of a cathode ray electron beam

Also Published As

Publication number Publication date
AT160907B (de) 1943-08-24
GB493751A (en) 1938-10-13
FR835462A (fr) 1938-12-22

Similar Documents

Publication Publication Date Title
US2181850A (en) Cathode ray tube
US2183309A (en) Electron multiplier
US2259507A (en) Electronic relay device
US2138928A (en) Electron discharge device
US2288402A (en) Television transmitting tube
US2190069A (en) Space discharge device
US2579351A (en) Isocon pickup tube
US2203048A (en) Shielded anode electron multiplier
US2905847A (en) High compression beam generating system especially for velocity modulated tubes
US2760096A (en) Television pickup tube
US2248977A (en) Electro-optical device
US2213174A (en) Television transmitting tube
US2256462A (en) Television transmitting device
US2840755A (en) Large storage low noise image tube
US2412086A (en) Image dissector tube
GB768021A (en) Improvements in or relating to electronic storage tubes and circuit arrangements therefor
US2266621A (en) Cathode ray tube system
US2540637A (en) Pickup tube system
US2213176A (en) Television transmitting tube
US2971108A (en) Electron discharge device
US2822493A (en) Graphechon storage tube
US2617954A (en) Pickup tube
US2292111A (en) Image dissector
EP0084915B1 (de) Fernsehkameraröhre
US2520240A (en) Cathode-ray tube