EP0876678A1 - Photomultiplicateur - Google Patents

Photomultiplicateur

Info

Publication number
EP0876678A1
EP0876678A1 EP96901061A EP96901061A EP0876678A1 EP 0876678 A1 EP0876678 A1 EP 0876678A1 EP 96901061 A EP96901061 A EP 96901061A EP 96901061 A EP96901061 A EP 96901061A EP 0876678 A1 EP0876678 A1 EP 0876678A1
Authority
EP
European Patent Office
Prior art keywords
layer
photocathode
layers
electron multiplying
anode
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.)
Withdrawn
Application number
EP96901061A
Other languages
German (de)
English (en)
Inventor
Duncan James Westland
Vladimir Skarda
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.)
ERA Patents Ltd
Original Assignee
ERA Patents Ltd
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 ERA Patents Ltd filed Critical ERA Patents Ltd
Publication of EP0876678A1 publication Critical patent/EP0876678A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J43/00Secondary-emission tubes; Electron-multiplier tubes
    • H01J43/04Electron multipliers

Definitions

  • the present invention relates to a photomultiplier device.
  • a photocathode which usually includes a photosensitive alkali metal, which emits photoelectrons in response to the incident photons.
  • the photoelectrons strike a first dynode, which emits secondary electrons, thereby multiplying the original photoelectrons.
  • the emitted electrons impinge on subsequent downstream dynodes, each emitting secondary electrons, thereby further multiplying the electrons.
  • the potential difference between adjacent dynodes is typically 100 V, and this multiplies the electrons by a factor of around 10 for each dynode.
  • the electrons emitted from the array of dynodes are detected by an anode, which gives an output which is a function of the intensity of the radiation incident upon the photocathode.
  • All of the components are provided in a vacuum envelope, normally made of metal, ceramic or glass, which includes a transparent face through which photons pass to the photocathode.
  • the material from which the photocathode is made depends on the radiation which is to be detected, for example whether the photomultiplier is to detect visible light, infra-red, ultra-violet, X-ray or gamma-ray radiation.
  • Typical photo ultipliers have a gain of about l million, although this can be increased by the provision of additional dynodes.
  • the problem with conventional photomultiplier tubes is their large size. Accordingly photodiodes and other solid state detectors have been increasingly used. These devices have the advantage of being smaller, less expensive, and do not need as high a voltage as photomultiplier tubes, however they are not as sensitive as photomultiplier tubes unless they are cooled to cryogenic temperatures.
  • a photomultiplier device comprises a plurality of layers bonded together, the layers including a photocathode layer for emitting photoelectrons when a photon is incident upon it, an electron multiplying layer for multiplying the electrons emitted from the photocathode, and an anode layer upon which the electrons emitted from the electron multiplying layer are incident.
  • the photomultiplier device By forming the photomultiplier device from a plurality of layers bonded together, rather than from discrete components provided in a vacuum envelope as with conventional devices, the device can be miniaturized. Further, microengineering techniques can be used in the manufacture of the device, making production costs similar to those for other solid state devices.
  • the photocathode layer, the electron multiplying layer and the anode layer are separated from each other by spacer members, and that the cavity between the layers is evacuated. This gives improved transmission of electrons between the layers.
  • the photocathode layer is preferably formed by coating a photoresponsive layer on a transparent substrate layer.
  • the transparent substrate layer forms a window through which photons pass to the photocathode.
  • the coating may be etched to remove selectively the photoresponsive material and allow bonding of spacers or the electron multiplying layer to the substrate layer.
  • the photocathode may be coated directly onto the electron multiplying layer.
  • the electron multiplying layer is advantageously a microchannel plate. This has the advantage of being thin and flat compared to an array of dynodes. A plurality of electron multiplying layers may be provided in series to increase the amplification of electrons.
  • the photocathode layer, the electron multiplying layer and the anode layer are each formed on or from a wafer which, when bonded together, may be diced to form a plurality of discrete devices.
  • anode layer is advantageous for the anode layer to be a resistive anode or a segmented anode. This allows the photomultiplier to give positional information relative to the incident radiation.
  • a method of manufacturing a photomultiplier device comprises forming a photocathode layer for emitting photoelectrons when a photon is incident upon it, an electron multiplying layer for multiplying electrons emitted by the photocathode layer, and an anode layer, and bonding the plurality of layers together.
  • the photocathode layer is formed by coating a photoresponsive material on a transparent substrate, the photocathode layer subsequently being bonded to one face of the electron multiplying layer.
  • the photocathode layer may be bonded to a spacer which is in turn bonded to the electron multiplying layer, and the electron multiplying layer may be bonded to a further spacer which is in turn bonded to the anode layer.
  • the transparent substrate, the electron multiplying layer, and the anode layer are in the form of wafers, in which case the method may include the additional step of dicing the wafers after bonding to form a plurality of discrete devices.
  • Figure 1 shows a first example
  • Figure 2 shows a second example
  • Figure 3 shows a third example
  • Figure 4 shows a resistive anode for use in any of the examples.
  • Figure 1 shows a first example of a photomultiplier device according to the present invention.
  • a transparent substrate 1 of glass, quartz or sapphire is provided, and is etched to form a number of window recesses.
  • the recesses are formed by a dissolution in a liquid or flux of energetic or reactive atoms, or ions.
  • a photoresponsive material 2 is then coated in each window recess.
  • the photocathode material 2 may be, for example gallium arsenide, indium phosphide, or other mixture of alkali metals and their compounds which emit electrons when radiation is incident upon them.
  • the photocathode material 2 may be selectively etched to allow for bonding of spacer members 3 to the transparent substrate 1.
  • the spacer members 3 are bonded using any suitable bonding method, for example by adhesive, fusion, solder or anodic bonding.
  • a microchannel plate 4 is bonded to the spacer members 3 by a suitable bonding method in spaced apart, confronting relation to the photocathode 2.
  • the microchannel plate is conventional in construction and comprises an array of channels, each having a diameter of around lO ⁇ m. Each channel has a semiconductor photosensitive inner surface. An electric field is applied along the length of each channel. When a photon is incident on the semiconductor surface, secondary electrons are emitted. These secondary electrons impinge on the semiconductor surface, causing further secondary electrons to be emitted, causing multiplication of the photoelectron.
  • Appropriate microchannel devices are available commercially from Hamamatsu Photonics KK (Shizuoka-Ken, Japan) and others.
  • the channels of the microchannel plate may be provided at an angle with respect to the face of the plate. This prevents positive ions from residual gases in the photomultiplier from being accelerated along the channels, and causing stray electron emissions.
  • Spacer members 5 are bonded to the face of the microchannel plate 4 opposite the photocathode 2, and an anode layer 6 is bonded onto these spacers 5.
  • the volumes between the photocathode 2 and the microchannel plate 4, and between the microchannel plate 4 and the anode 6 are evacuated.
  • the bonded layers are cut, or diced, perpendicular to the layers to divide the layers into a plurality of discrete devices.
  • photons are transmitted through the window 1, and onto the photocathode layer 2.
  • the photocathode layer 2 emits photoelectrons in response to the photons incident upon it, and these are transmitted to the microchannel plate 4.
  • the microchannel plate multiplies the photoelectrons striking it, and transmits electrons towards the anode layer 6, where they are detected.
  • the photocathode 2 , microchannel plate 4 and anode layer 6 are all biased with a voltage to ensure the electrons generated are accelerated towards the anode layer 6.
  • Figure 2 shows a second example of the present invention.
  • the photocathode layer 2 is bonded directly onto one face of the microchannel plate 4, and the anode layer 6 is bonded directly onto the opposite face of the microchannel plate 4.
  • the transparent substrate 1 is not etched to form recessed before the formation of the photocathode layer 2.
  • the transparent substrate 1 can be omitted, providing the device is to be used in a vacuum.
  • a plurality of microchannel plates may be bonded together in series. Such a device is shown in Figure 3.
  • a segmented anode may be provided.
  • the voltage of each segment can be monitored to identify the position.
  • a resistive anode 10 can be used.
  • Such an anode 10 is a resistive sheet connected to a positive supply via resistors R, at various locations on the anode 10.
  • resistors R resistors
  • position detection may be achieved by providing an array of detectors.
  • the array may be a one or two dimensional array.

Landscapes

  • Electron Tubes For Measurement (AREA)

Abstract

La présente invention concerne un photomultiplicateur constitué par un certain nombre de couches (2, 4, 6) liées les unes aux autres. Il s'agit d'une couche photocathodique (2) qui émet des photoélectrons quand elle reçoit un photon, d'une couche (4) multiplicatrice des électrons qu'émet la photocathode (2) et d'une couche anodique (6) qui reçoit les électrons émis par la couche multiplicatrice (4). Les différentes couches (2, 4, 6) peuvent être espacées par des éléments d'écartement (3, 5) et la cavité comprise entre elles peut être mise sous vide. La couche photocathodique (2) peut être formée à partir d'un revêtement photosensible sur un support transparent (1). La couche multiplicatrice d'électrons (4) peut être une plaque à microcanaux. Les différentes couches (2, 4, 6) peuvent avoir la forme de plaquettes. Dans ce cas, la fabrication de l'appareil comprend une opération de découpage en dés des plaquettes après que les couches ont été liées entre elles, pour former de nombreux composants distincts.
EP96901061A 1996-01-25 1996-01-25 Photomultiplicateur Withdrawn EP0876678A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/GB1996/000178 WO1997027615A1 (fr) 1996-01-25 1996-01-25 Photomultiplicateur

Publications (1)

Publication Number Publication Date
EP0876678A1 true EP0876678A1 (fr) 1998-11-11

Family

ID=10786639

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96901061A Withdrawn EP0876678A1 (fr) 1996-01-25 1996-01-25 Photomultiplicateur

Country Status (3)

Country Link
EP (1) EP0876678A1 (fr)
GB (1) GB9815891D0 (fr)
WO (1) WO1997027615A1 (fr)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3408532A (en) * 1965-12-06 1968-10-29 Northrop Corp Electron beam scanning device
FR2676862B1 (fr) * 1991-05-21 1997-01-03 Commissariat Energie Atomique Structure multiplicatrice d'electrons en ceramique notamment pour photomultiplicateur et son procede de fabrication.
US5264693A (en) * 1992-07-01 1993-11-23 The United States Of America As Represented By The Secretary Of The Navy Microelectronic photomultiplier device with integrated circuitry
FI940740A0 (fi) * 1994-02-17 1994-02-17 Arto Salokatve Detektor foer paovisning av fotoner eller partiklar, foerfarande foer framstaellning av detektorn och maetningsfoerfarande

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9727615A1 *

Also Published As

Publication number Publication date
WO1997027615A1 (fr) 1997-07-31
GB9815891D0 (en) 1998-09-16

Similar Documents

Publication Publication Date Title
JP4246995B2 (ja) 電子線検出器、走査型電子顕微鏡、質量分析装置、及び、イオン検出器
US5329110A (en) Method of fabricating a microelectronic photomultipler device with integrated circuitry
EP1717843B1 (fr) Photomultiplicateur et sa méthode de fabrication
EP2380047B1 (fr) Photocathode améliorée à sommets de cube
EP0642147B1 (fr) Photo-émetteur, tube à électrons, et photodétecteur
JPH08148113A (ja) 光電子増倍管
EP2577704B1 (fr) Structure de multiplication d'électrons destinée à être utilisée dans un tube à vide au moyen d'une multiplication d'électrons et tube à vide faisant appel à une multiplication d'électrons et pourvu d'une telle structure de multiplication d'électrons
US6492657B1 (en) Integrated semiconductor microchannel plate and planar diode electron flux amplifier and collector
JPH09213206A (ja) 透過型光電面、その製造方法、及びそれを用いた光電変換管
US6521149B1 (en) Solid chemical vapor deposition diamond microchannel plate
EP3400469B1 (fr) Intensificateur d'image pour un dispositif de vision nocturne
US6215232B1 (en) Microchannel plate having low ion feedback, method of its manufacture, and devices using such a microchannel plate
JP4607866B2 (ja) 画像増強装置及びそのための電子増倍装置
US5500531A (en) Sensor for detecting ultra-violet rays
JP2003338260A (ja) 半導体光電面とその製造方法、及びこの半導体光電面を用いた光検出管
US7208874B2 (en) Transmitting type secondary electron surface and electron tube
GB2293685A (en) Photomultipliers
WO1997027615A1 (fr) Photomultiplicateur
JP5135114B2 (ja) 光電陰極およびその製造方法並びに光電子増倍管
GB2269048A (en) Photoemitters
EP3631299B1 (fr) Film semi-conducteur et détecteur de lumière à phototube
JP2009217996A (ja) 光電陰極、電子管及びイメージインテンシファイア
JP2944045B2 (ja) 増倍部付き光電面
JPH10241555A (ja) 透過型光電陰極
JPH10172503A (ja) 光電子増倍管

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19980813

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI NL PT SE

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SKARDA, VLADIMIR

Inventor name: WESTLAND, DUNCAN JAMES

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

17Q First examination report despatched

Effective date: 19990312

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19991030