US3212021A - Signal amplifier of the electron multiplier type - Google Patents

Signal amplifier of the electron multiplier type Download PDF

Info

Publication number
US3212021A
US3212021A US72450A US7245060A US3212021A US 3212021 A US3212021 A US 3212021A US 72450 A US72450 A US 72450A US 7245060 A US7245060 A US 7245060A US 3212021 A US3212021 A US 3212021A
Authority
US
United States
Prior art keywords
resistor
voltage
dynodes
electrodes
signal
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
US72450A
Other languages
English (en)
Inventor
Melvin L Erickson
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.)
Maxar Space LLC
Original Assignee
Philco Ford 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 NL271313D priority Critical patent/NL271313A/xx
Application filed by Philco Ford Corp filed Critical Philco Ford Corp
Priority to US72450A priority patent/US3212021A/en
Priority to FR876350A priority patent/FR1303952A/fr
Priority to DEP28310A priority patent/DE1237226B/de
Priority to GB42651/61A priority patent/GB932160A/en
Application granted granted Critical
Publication of US3212021A publication Critical patent/US3212021A/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
    • H01J43/30—Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for

Definitions

  • This invention relates to signal amplifiers and more particularly to signal amplifiers of the electron multiplier type wherein different electron velocities and consequent different transit times between successive electrodes tend to introduce phase variations in the signal.
  • an electron multiplier comprises a cathode which emits primary electrons, a plurality of spaced secondary electron emissive electrodes known as dynodes, the first of which is impinged by the primary electrons from the cathode, and a collector electrode or anode which receives the secondary electrons from the last secondary electron emissive electrode, and from which the output signal may be derived. Accelerating voltages are applied to the secondary electron emissive electrodes which constitute successive multiplier stages.
  • phase shift of a signal is highly undesirable is a color television receiver which employs a color image-producing cathode ray tube of the index type.
  • a color image-producing cathode ray tube of the index type In the preferred form of such tube there are color image-producing stripes and index stripes on the screen which are impinged by electrons in the course of scanning of the screen in successive lines transversely of the stripes.
  • the index stripes serve to produce an index signal which is utilized to effect proper time coordination between beam position and modulation, such coordination being essential to proper color rendition in the production of the color image.
  • the phase of the index signal is representative of beam position, and any appreciable phase shift of the index signal cannot be tolerated as it would cause noticeable error in the color image.
  • the index stripes emit invisible light in response to electron impingement thereof, and a photomultiplier tube is employed to translate such light into an electrical signal.
  • a photomultiplier tube is, of course, an electron multiplier.
  • an index signal of substantially constant amplitude it is desirable to provide for automatic gain control in the photomultiplier as previously mentioned. However, this gives rise to phase variation of the signal which in this instance is highly undesirable.
  • the principal object of the present invention is to provide a signal amplifier of the electron multiplier type wherein such phase variation is substantially prevented.
  • accelerating voltages are applied to the successive electrodes. This is done conveniently by deriving such voltages from taps on a voltage divider connected to a source of unidirectional voltage.
  • a resistor is connected in series with one of the secondary electron emissive electrodes, i.e. between that electrode and its divider tap, to provide automatic gain control
  • the voltage produced across said resistor increases 3,212,021 Patented Oct. 12, 1965 the voltage difference between that electrode and the preceding electrode and decreases the voltage difference between that electrode and the succeeding electrode.
  • automatic gain control is effeced but transit time variation is introduced which. causes corresponding variation in the phase of the signal.
  • the undesirable phase variation is substantially prevented by effecting compensation within the electron multiplier.
  • this is accomplished by selection of values of the circuit elements associated with the controlled dynode.
  • the desired cancellation is effected. both by selection of values of said circuit elements and by the provision of an additional circuit element connected to the anode.
  • FIG. 1 is a diagrammatic illustration of a signal amplifier according to one embodiment of the present invention
  • FIG. 2 is an explanatory diagrammatic illustration
  • FIG. 3 is a diagrammatic illustration of a signal amplifier according to another embodiment of the invention.
  • a signal amplifier including a conventional photomultiplier tube 10 such as might be used in a color television system of the type hereinbefore mentioned.
  • the photomultiplier comprises a photocathode 11, an anode 12, and a series of secondary electron emissive electrodes, i.e. dynodes, there being six such electrodes in the illustrated photomultiplier designated 1 to 6. Accelerating voltages are applied to the dynodes from tap points of a voltage divider comprising series-connected resistors 13 to 19. The voltage divider is connected in series with a source of unidirectional voltage represented as a battery 20.
  • the photocathode 11 In operation the photocathode 11 emits primary electrons in response to light impinging thereon. Due to the location of the first dynode 1 and the accelerating voltage applied thereto, the primary electrons impinge said dynode and cause it to emit a multiplied number of secondary electrons. These secondary electrons are drawn successively to the other dynodes under control of their accelerating voltages. In each dynode stage a multiplication takes place so that the operation involves a series of multiplying actions according to the number of dynode stages.
  • the amplified signal is derived from across the inductor 21 connected to the anode 12.
  • a resistor 22 is included in the tap connection leading to the dynode 5. As is well understood, this effects automatic gain control by varying the accelerating voltages applied to dynodes 5 and 6. However, it introduces the aforementioned undesirable phase shift in the signal as will now be explained.
  • the voltage differentials between dynodes 4 and 5 and between dynodes 5 and 6 are changed by the unidirectional voltage across resistor 22.
  • the latter voltage adds to th voltage across resistor 17 and subtracts from the voltage across resistor 18. It thus increases the voltage differential between dynodes 4 and 5 and decreases the voltage dilferential between dynodes 5 and 6. The effect of this is to decrease the transit time between dynodes 4 and and to increase the transit time between dynodes 5 and 6.
  • the transit time between two successive dynodes is given by the equation K 1 tr w where t is the transit time, K is a constant, d is the distance between the dynodes, and V is the voltage differential between the dynodes. Since d is contant, the transit time varies inversely as the square root of the voltage differential between the dynodes. Thus the transit times between dynodes 4 and 5 and between dynodes 5 and 6 vary in inverse relation to the square root of the voltage differentials. The result of these transit time variations is to introduce phase shift into the signal.
  • FIG. 1 is the embodiment of FIG. 1 the undesired phase variation is substantially prevented by selection of the values of the circuit elements associated with the controlled dynode 5. This will be explained with the aid of FIG. 2 wherein there is shown only the portion of the system which is of concern.
  • the transit times between dynodes 4 and 5 and between dynodes 5 and 6 will be equal if the ratio of the distances al and d is equal to the ratio of the square roots of the voltage differentials between dynodes 4 and 5 and between dynodes 5 and 6.
  • resistors 17 and 18 are given values such that E is less than E
  • resistor 22 is given a value such that the voltage IR thereacross is equal to one-half the difference between the voltages E and E
  • FIG. 3 there is shown another embodiment of the invention in which the undesired phase shift is substantially eliminated in a different manner.
  • the voltage across resistor 22a decreases the transit time between dynodes 4 and 5 and causes phase shift.
  • resistor 18a is made substantially smaller than resistor 17a, e.g. one-half the size of resistor 17a. Therefore, the voltage across resistor 18a is so small that with the subtraction of the voltage across 5&- sistor 22a the voltage on dynode 6 is so small that it is incapable of attracting the electrons which instead are attracted directly to the anode 12, by-passing dynodes 6.
  • a resistor 23 is included in the connection between anode 12 and ground. This resistor does not affect the automatic gain control action.
  • the voltage across resistor 23 due to current flow therethrough applies a negative bias to the anode and thus increases the transit time between dynode 5 and the anode, compensating for the decreased transit time between dynodes 4 and 5. While thus effecting compensation, resistor 23 does not affect the automatic gain control.
  • an electron multiplier including a series of at least three spaced secondary electron emissive electrodes, means for applying biasing voltages between the first and second of said electrodes and between the second and third of said electrodes, and a resistor connected between said biasing means and said second electrode for providing automatic control of the gain of the amplifier, the parameter being such that where d, is the distance between the first and second electrodes, d is the distance between the second and third electrodes, E is the biasing voltage between the first and second electrodes, E is the biasing voltage between the second and third electrodes, I is the nominal current through said resistor, and R is the resistance of said resistor, whereby the electron transit times between the first and second electrodes and between the second and third electrodes are caused to be substantially equal.
  • an electron multiplier including a series of at least three equally spaced secondary electron emissive electrodes, means for biasing the second of said electrodes positively with respect to the first electrode by a predetermined amount, means for biasing the third electrode positively with respect to the second electrode by a greater amount, and a resistor connector between said biasing means and said second electrode for providing automatic control of the gain of the amplifier, the parameters being such that 2 1 I R- 2 where E is the bias voltage supplied by said first means, E is the bias voltage supplied by said second means, I is the nominal value of current through said resistor, and R is the resistance of said resistor, whereby the electron transit times between the first and second electrodes and between the second and third electrodes are caused to be substantially equal.

Landscapes

  • Amplifiers (AREA)
  • Processing Of Color Television Signals (AREA)
US72450A 1960-11-29 1960-11-29 Signal amplifier of the electron multiplier type Expired - Lifetime US3212021A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL271313D NL271313A (OSRAM) 1960-11-29
US72450A US3212021A (en) 1960-11-29 1960-11-29 Signal amplifier of the electron multiplier type
FR876350A FR1303952A (fr) 1960-11-29 1961-10-18 Amplificateur de signal
DEP28310A DE1237226B (de) 1960-11-29 1961-11-27 Betriebsschaltung fuer einen Elektronen-vervielfacher als Signalverstaerker
GB42651/61A GB932160A (en) 1960-11-29 1961-11-29 Improvements in and relating to signal amplifiers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US72450A US3212021A (en) 1960-11-29 1960-11-29 Signal amplifier of the electron multiplier type

Publications (1)

Publication Number Publication Date
US3212021A true US3212021A (en) 1965-10-12

Family

ID=22107664

Family Applications (1)

Application Number Title Priority Date Filing Date
US72450A Expired - Lifetime US3212021A (en) 1960-11-29 1960-11-29 Signal amplifier of the electron multiplier type

Country Status (5)

Country Link
US (1) US3212021A (OSRAM)
DE (1) DE1237226B (OSRAM)
FR (1) FR1303952A (OSRAM)
GB (1) GB932160A (OSRAM)
NL (1) NL271313A (OSRAM)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2909220A1 (fr) * 2006-11-29 2008-05-30 Photonis Soc Par Actions Simpl Procede d'egalisation de gain et de temps de transit de voies de tube photomultiplicateur.
CN102822939A (zh) * 2010-03-31 2012-12-12 赛默菲尼根有限责任公司 具有动态增益控制的离散倍增电极检测器

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2432654A (en) * 1943-12-02 1947-12-16 Farnsworth Res Corp Electron multiplier gain control
US2553565A (en) * 1946-10-07 1951-05-22 Farnsworth Res Corp High efficiency class c multiplier
US2585044A (en) * 1945-02-05 1952-02-12 Farnsworth Res Corp Gain control apparatus
US2798165A (en) * 1956-04-12 1957-07-02 Leland K Neher Stable photomultiplier amplifier
US2840720A (en) * 1956-03-19 1958-06-24 Albert B Van Rennes Multiplier phototube stabilizing circuit

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE881400C (de) * 1939-08-21 1953-06-29 Bosch Gmbh Robert Schaltanordnung fuer Elektronenvervielfacher

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2432654A (en) * 1943-12-02 1947-12-16 Farnsworth Res Corp Electron multiplier gain control
US2585044A (en) * 1945-02-05 1952-02-12 Farnsworth Res Corp Gain control apparatus
US2553565A (en) * 1946-10-07 1951-05-22 Farnsworth Res Corp High efficiency class c multiplier
US2840720A (en) * 1956-03-19 1958-06-24 Albert B Van Rennes Multiplier phototube stabilizing circuit
US2798165A (en) * 1956-04-12 1957-07-02 Leland K Neher Stable photomultiplier amplifier

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2909220A1 (fr) * 2006-11-29 2008-05-30 Photonis Soc Par Actions Simpl Procede d'egalisation de gain et de temps de transit de voies de tube photomultiplicateur.
CN102822939A (zh) * 2010-03-31 2012-12-12 赛默菲尼根有限责任公司 具有动态增益控制的离散倍增电极检测器
CN102822939B (zh) * 2010-03-31 2015-11-25 赛默菲尼根有限责任公司 具有动态增益控制的离散倍增电极检测器
US9293307B2 (en) 2010-03-31 2016-03-22 Thermo Finnigan Llc Discrete dynode detector with dynamic gain control

Also Published As

Publication number Publication date
FR1303952A (fr) 1962-09-14
NL271313A (OSRAM)
GB932160A (en) 1963-07-24
DE1237226B (de) 1967-03-23

Similar Documents

Publication Publication Date Title
GB2098796A (en) Electron multiplier comprising microchannel plates and an amplifier dynode stage connected thereto and method of manufacturing same
US3212021A (en) Signal amplifier of the electron multiplier type
US3003110A (en) Image transforming apparatus with cross modulation suppression means
US2675469A (en) Integrating circuit arrangement
US4053927A (en) Chrominance amplifier control circuit providing simultaneous adjustment of gain and DC level
US2777018A (en) Direct-coupled amplifier
US2474435A (en) Vacuum tube amplifier
US2137278A (en) Amplifier system
US3089959A (en) Self-limiting photomultiplier amplifier circuit
US2172859A (en) Electron tube circuits
US2305179A (en) Electron multiplier
US3271699A (en) Balanced modulator having the anode of a multiplier phototube directly connected to the cathode of the modulator tube
US2220452A (en) Electronic device
Theile On the signal-to-noise ratio in television storage tubes
US3067360A (en) Photo-multiplier circuits
US2954475A (en) Television camera or like head amplifier arrangements
US2556824A (en) Cathode-ray tube
GB499487A (en) Improvements in or relating to electron discharge devices for voltage amplification or control
US2579528A (en) Differential electronic amplifier
US2773117A (en) Cathode ray tube beam intensity control
US2585044A (en) Gain control apparatus
US2226260A (en) Synchronizing circuit
US2311981A (en) Electron control device
US2432654A (en) Electron multiplier gain control
US2960564A (en) Indexing in color television receivers