US2180279A - Method of operating electron multipliers - Google Patents

Method of operating electron multipliers Download PDF

Info

Publication number
US2180279A
US2180279A US132329A US13232937A US2180279A US 2180279 A US2180279 A US 2180279A US 132329 A US132329 A US 132329A US 13232937 A US13232937 A US 13232937A US 2180279 A US2180279 A US 2180279A
Authority
US
United States
Prior art keywords
electrons
electron
multiplication
multiplier
cathode
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
US132329A
Other languages
English (en)
Inventor
Philo T Farnsworth
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.)
Farnsworth Television and Radio Corp
Original Assignee
Farnsworth Television and Radio 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
Priority to NL51159D priority Critical patent/NL51159C/xx
Priority to BE427109D priority patent/BE427109A/xx
Application filed by Farnsworth Television and Radio Corp filed Critical Farnsworth Television and Radio Corp
Priority to US132329A priority patent/US2180279A/en
Priority to GB6212/38A priority patent/GB515297A/en
Priority to FR835581D priority patent/FR835581A/fr
Application granted granted Critical
Publication of US2180279A publication Critical patent/US2180279A/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
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/76—Dynamic electron-multiplier tubes, e.g. Farnsworth multiplier tube, multipactor

Definitions

  • multipliers energized by alternating current; to provide alternating current of special wave form for the operation of electron multipliers; and to provide a method of reducing shot effect in an electron multiplier.
  • My invention possesses numerous other objects and features of advantage, some of which,'together with the foregoing, will be set forth in 5 the following description of specific apparatus embodying and utilizing my novel method. It is therefore to be understood that my method is applicable to other apparatus, and that I do not limit myself, in any way, to the apparatus of the present application, as I may adopt various other apparatus embodiments, utilizing the method, within the scope of the appended claims.
  • Figure 1 is a graph illustrating the electron multiplication in an electron multiplier supplied with a-voltage of sinusoidal wave form.
  • Figure-2 is a diagram, reduced to the simplest terms, of a diode electron multiplier and circuit.
  • Figure 3 is a graph showing-a special wave form which may be used in conjunction with the energization of the device of Figure 2.
  • Figure 4 is a diagrammatic drawing and circuit, in simplified form, of another modification of an electron multiplier and circuit.
  • Figure 5 is a drawing of a wave form which may be used in conjunction with the device of Figure 4.
  • My invention relates to electron multipliers source, it is common to direct these electrons to be multiplied through an aperture in the device so that they may come within the influence of the oscillating fields.
  • each of the incoming electrons be multiplied by the same num- 10 her of impacts as every other incoming electron.
  • My present invention comprises a method of reducing the shot effect by using'a non-sinusoidal driver. 15
  • an envelope I is provided as a part of an envelope of another device, not shown, wherein electrons are emitted into space and thereafter travel into-the envelope I.
  • the incoming elec- '25 trons to be multiplied are represented as arriving along a direction indicated by arrow 2.
  • multiplier itself, in this case, comprises the wellknown Farnsworth diode having an exterior cathode cylinder 4 and an interior apertured 0. anode 5 in the electron path.
  • the cathode cylinder 4 has its inner surface sensitized or otherwise treated so that electrons, will be produced at a ratio greater than unity when impacted by an electron traveling, for ex- 35 ample, with a velocity of 20 electron volts or more. Multiplication ratios up to 1 to 12 may be obtained.
  • An aperture 5 is provided in the cathode 4 through which the electrons to be multiplied may 40 enter the multiplier structure itself. It is obvious that the size of this aperture may be varied in accordance wtih the size of the electron beam.
  • the electrodes themselves are energized by being connected through a series circuit comprising a resonant circuit 1 and a series condenser 9. Further, the cathode is connected to the negative terminal of a battery8, the positive terminal of which is at ground potential.
  • the anode 5 is provided with a steady positive accelerating potential with respect to the cathode 4 by connecting one side of the tuned circuit to ground, thus completing the connection to the anode,
  • a driver oscillator I is coupled to the tuned circuit 1. I prefer to so adjust the constants of the tuned circuit 1 and the value of the accelerating potential between the cathode 4 and 5 the anode 5 that more than one electron impact may take place per cycle. If the anode voltage with respect to ground which is represented by the line g-t of Figure l is plotted against time,
  • the electrons entering the multiplier over the entire multiplying period of the radio-frequency cycle from A to E experience a multiplication, but .the ratio of multiplication differs tremenduously with the time at which the electron enters the multiplier.
  • the radio-frequency cycle is divided into an accumulation period from A to B, and a multiplying period from B to C; collection takes place at all times, but collection alone takesplace in the period from C to D.
  • solenoid II is provided around the tube and is energized by solenoid source l2 so that a strong magnetic field perpendicular to the cathode surfaces is obtained. This magnetic field prevents the electrons from being immediately collected by the anode ring 5, and they will not be collected until their velocity is low.
  • Generator I0 is then connected to energize the anode and the two cathodes connected together, and drives the device with a voltage of nonsinusoidal wave form of the shape, for example, shown in Figure 5.
  • the usual steady acceleration potential is provided on the anode.
  • the output may be taken oil across the resonant cir- 'cuit 1.
  • an electron to be multiplied enters the multiplication chamber through cathode aperture 6 at time A on the voltage wave shown creased again.
  • the entering electrons travel back and forth without striking the oathodes, nor are they collected by the anode 5.
  • the maximum potential difierence is at time B, and the time of flight, therefore, will be the shortest at that time. Beyond point B in the time cycle, the electrons will be able to strike the cathodes as the potential difference rapidly decreases. Multiplication, therefore, takes place at high ratios until the potential difference reaches its minimum value at time C. From to D the electrons are decelerated and collection occurs by the anode 5.
  • This mode of operation has an advantage over the previously described mode in that the entire swing of the potential difference can be made useful for the multiplication of the accumulated electrons.
  • the. cathode may be photo-electric and itself generate, under the influence of light, the initial electrons.
  • My method therefore, is applicable to all arrangements wherein multiplication of elecratio multiplication for a relatively long portion of the cycle and then to a relatively high-ratio multiplication for a relatively short portion of the cycle.
  • an electron multiplier wherein electrons are oscillated against and away from a surface adapted to emit secondary electrons upon electron impact therewith, the method of operation which comprises oscillating the electrons without impact for a predetermined time and thereafter continuing theoscillation with impact to produce multiplication.
  • the method of. operation which comprises supplying electrons in a continuous. stream, accumulating electrons by oscillating the electrons without impact for a predetermined -time and thereafter continuing the oscillation with impact to produce multiplication.

Landscapes

  • Electron Tubes For Measurement (AREA)
  • Cold Cathode And The Manufacture (AREA)
US132329A 1937-03-22 1937-03-22 Method of operating electron multipliers Expired - Lifetime US2180279A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL51159D NL51159C (enrdf_load_stackoverflow) 1937-03-22
BE427109D BE427109A (enrdf_load_stackoverflow) 1937-03-22
US132329A US2180279A (en) 1937-03-22 1937-03-22 Method of operating electron multipliers
GB6212/38A GB515297A (en) 1937-03-22 1938-02-28 Method of operating electron multipliers
FR835581D FR835581A (fr) 1937-03-22 1938-03-22 Procédé de fonctionnement d'un multiplicateur d'électrons

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US132329A US2180279A (en) 1937-03-22 1937-03-22 Method of operating electron multipliers

Publications (1)

Publication Number Publication Date
US2180279A true US2180279A (en) 1939-11-14

Family

ID=22453516

Family Applications (1)

Application Number Title Priority Date Filing Date
US132329A Expired - Lifetime US2180279A (en) 1937-03-22 1937-03-22 Method of operating electron multipliers

Country Status (5)

Country Link
US (1) US2180279A (enrdf_load_stackoverflow)
BE (1) BE427109A (enrdf_load_stackoverflow)
FR (1) FR835581A (enrdf_load_stackoverflow)
GB (1) GB515297A (enrdf_load_stackoverflow)
NL (1) NL51159C (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2565585A (en) * 1946-09-24 1951-08-28 Raytheon Mfg Co Electron-discharge device of the magnetron type

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2565585A (en) * 1946-09-24 1951-08-28 Raytheon Mfg Co Electron-discharge device of the magnetron type

Also Published As

Publication number Publication date
FR835581A (fr) 1938-12-26
BE427109A (enrdf_load_stackoverflow)
GB515297A (en) 1939-12-01
NL51159C (enrdf_load_stackoverflow)

Similar Documents

Publication Publication Date Title
USRE22990E (en) Modulation system
US4453108A (en) Device for generating RF energy from electromagnetic radiation of another form such as light
US2305883A (en) Frequency multiplier
US2278210A (en) Electron discharge device
US2242275A (en) Electrical translating system and method
US2173193A (en) High-frequency oscillator
US2086904A (en) Frequency multiplier
GB477668A (en) Improvements in or relating to electron discharge devices and arrangements for use on very short waves
US2289952A (en) Electron gun
US2401945A (en) Frequency multiplier
US2638561A (en) Cathode-ray oscillator tube
US2180279A (en) Method of operating electron multipliers
US2645739A (en) Electron discharge apparatus
US2071516A (en) Oscillation generator
US2466704A (en) Frequency multiplier apparatus
US2138920A (en) Secondary emission tube and circuit
US2487800A (en) Frequency multiplier and stabilization cavity resonator apparatus
US2139813A (en) Secondary emission electrode
US2140832A (en) Means and method of controlling electron multipliers
US2121067A (en) Double cathode electron discharge device and circuits
US2071517A (en) Multipactor phase control
US2307693A (en) Frequency multiplier
US2150573A (en) Electric discharge device
US3378718A (en) Crossed-field traveling wave electron reaction device employing cyclotron mode interaction
US2889488A (en) Delay lines for crossed field tubes