EP0013235A1 - Elektronenvervielfachungsvorrichtung mit axialem magnetischem Feld - Google Patents

Elektronenvervielfachungsvorrichtung mit axialem magnetischem Feld Download PDF

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Publication number
EP0013235A1
EP0013235A1 EP79401057A EP79401057A EP0013235A1 EP 0013235 A1 EP0013235 A1 EP 0013235A1 EP 79401057 A EP79401057 A EP 79401057A EP 79401057 A EP79401057 A EP 79401057A EP 0013235 A1 EP0013235 A1 EP 0013235A1
Authority
EP
European Patent Office
Prior art keywords
electron
bars
main axis
multiplier tube
tube according
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.)
Granted
Application number
EP79401057A
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English (en)
French (fr)
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EP0013235B1 (de
Inventor
Kei-Ichi Kuroda
Daniel Sillou
Fujio Takeuchi
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.)
Bpifrance Financement SA
Original Assignee
Agence National de Valorisation de la Recherche ANVAR
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.)
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Application filed by Agence National de Valorisation de la Recherche ANVAR filed Critical Agence National de Valorisation de la Recherche ANVAR
Priority to AT79401057T priority Critical patent/ATE6711T1/de
Publication of EP0013235A1 publication Critical patent/EP0013235A1/de
Application granted granted Critical
Publication of EP0013235B1 publication Critical patent/EP0013235B1/de
Expired legal-status Critical Current

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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
    • H01J43/18—Electrode arrangements using essentially more than one dynode
    • H01J43/22—Dynodes consisting of electron-permeable material, e.g. foil, grid, tube, venetian blind
    • 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
    • H01J43/14—Control of electron beam by magnetic field

Definitions

  • the present invention relates to electron multipliers, and more particularly to photomultiplier tubes.
  • the electron-multiplier tubes conventionally comprise, in an evacuated tubular chamber, first one or more electrodes and cathode directed source of electrons, then a series of electrodes capable of secondary emission of electrons, or dynodes, and finally an anode forming an electron collector.
  • These different electrodes are arranged along the main axis of the tube; in operation, they are subjected to potentials capable of creating an electric field accelerating the electrons along this same axis.
  • the electron source made of photosensitive material, is called photo-cathode.
  • dynodes In one type of electron multiplier (“box-type"), the dynodes each comprise a single element, and the dynodes together define a sort of box channeling the electrons, each dynode facing partly the previous one and partly to the next one.
  • box-type electron multiplier
  • the dynodes each comprise a single element, and the dynodes together define a sort of box channeling the electrons, each dynode facing partly the previous one and partly to the next one.
  • each dynode has a distributed structure comprising several active elements (ensuring secondary emission), which extend transversely to the main axis of the tube.
  • each dynode is made up of the rectangular mutually parallel mutually whose long side extends perpendicular to the main axis of the tube, while their short side is inclined on this same axis.
  • such dynodes are said to be “Venetian”, or of the "louver” type.
  • two consecutive dynodes have an alternating and symmetrical inclination relative to the main axis of the tube.
  • multi-channel electron multipliers are also known, in which the electrons arriving on the anode are distinguished according to the point of the cathode where they were generated. These multi-channel devices therefore have several associated anodes provided with as many electrical connections. Their dynode structures are diverse.
  • these multi-channel electron multipliers generally suffer from poor spatial resolution: they only distinguish a few well defined electronic impact zones at the level of the cathode. They do not in fact make it possible to establish a true general correspondence between the impact of an electron on the cathode and the impact on the anode of the electrons multiplied consequently by the dynodes.
  • the invention provides an electron multiplier capable of such a correspondence, which will hereinafter be called "localization".
  • the proposed electron multiplier tube is of the type comprising along an main axis an electron emitting surface, several stages of dynodes with distributed structure, capable of reflex electronic secondary emission, and an electron receiving surface , as well as means producing an electron accelerating electric field generally oriented along the main axis, from the electron emitting surface to the electron receiving surface.
  • dynode with a distributed structure capable of secondary reflex electronic emission
  • the dynodes comprise series or grids of elongated elements or bars, prismatic or cylindrical, and parallel, each grid being substantially perpendicular to the main axis of the tube.
  • a grid does not in itself offer any possibility of locating electrons along its large dimension, we also observe surprisingly, a roughly homogeneous spatial resolution in all directions perpendicular to the main axis of the tube.
  • each dynode stage it is also very advantageous for each dynode stage to be divided into several levels or sub-stages, offset between them so that the set of different sub-stages constituting a dynode is seen by the incident electrons almost as an opaque surface.
  • the small dimension of the bars in the plane. perpendicular to the main axis is less than about 1 mm, and the distance between two adjacent bars is at least equal to their small dimension. This jointly improves the spatial resolution and the gain. It is then desirable, although not absolutely necessary, for the electric field to be greater than 200 V / cm, and for the magnetic field to be greater than 50 Gauss. In the preferred embodiments of the invention, the small dimension of the bars is approximately 0.5 mm, and the electric field and the magnetic field are chosen correlatively to each other between approximately 400 and 1000 V / cm, and between about 100 and 500 Gauss, respectively.
  • each dynode comprises two grids of bars spaced along the main axis; in each grid the bars are spaced a distance equal to their small dimension; the two grids are offset from each other by a distance equal to their small dimension; and the electric and magnetic fields are correlatively chosen so that a secondary electron emitted by a bar of the first grid always passes statistically between the bars of the second grid (the word statistically means here that a secondary electron nevertheless retains a certain probability - very low - of reaching the bars of the second grid).
  • each dynode comprises n grids of bars spaced along the main axis; in each grid the bars are spaced n times their small dimension; the n grids are successively offset in the same direction by a distance equal to their small dimension each with respect to the previous one; and the electric and magnetic fields are correlatively chosen so that a secondary electron emitted by a bar of a grid on a parallel to the main axis passes statistically on the same parallel substantially at the levels of the following grid and the n-th wire rack.
  • the bars it is also advantageous for the bars to have a cross section symmetrical with respect to a plane parallel to the main axis of the tube and passing through the axis of their largest dimension. This provides better homogeneity of the electric field, and improves spatial resolution.
  • the cross section of the bars is of the isosceles right triangle triangle of hypotenuse directed downstream of the electronic trajectories, of the circular kind, or of the flat rectangle kind of predetermined inclination on the main axis, the bars then being slats.
  • other types of cross section can be envisaged.
  • the main application studied was that of photo-multipliers, but the invention applies generally to any type of electron multiplier tube whose dynodes, with distributed structure, are capable of secondary reflex emission.
  • the electron emitting and receiving surfaces which surround these dynodes can take different forms.
  • the electron-emitting surface can be an electron-emitting electrode, cathode or photocathode, or a surface transparent to electrons of external origin.
  • the electron receiving surface can be a divided anode with multiple connections, an electroluminescent surface or a mosaic surface which can be analyzed by electron beam, as will be seen below.
  • FIG. 1 is a schematic sectional view of a conventional photomultiplier tube with Venetian dynodes.
  • a photocathode 2 is arranged to receive a light beam L.
  • this cathode reacts to each photon by emitting a primary electron, channeled by an electrode 3.
  • the primary electrons are directed towards a series of 10 dynodes, referenced 4 to 13, and followed by an anode 14. All of the electrodes are polarized by potentials capable of creating an electron accelerating electric field from the cathode to the anode - main axis of the tube .
  • Each dynode, of distributed structure comprises a plurality of parallel and inclined lamellae which extend perpendicular to the plane of Figure 1, and extend vertically in the plane of Figure 1.
  • the slats are rectangular, 30 mm long and 3 mm wide; their short side is inclined at 45 0 on the main axis of the tube, the direction of inclination being alternated from one dynode to another.
  • the surface of the dynodes is made of material capable of secondary electronic emission, that is to say that, struck by an electron, each dynode will emit several secondary electrons on the side where the primary electron arrived. And the secondary electrons are in turn accelerated and led by the electric field to the next dynode.
  • Figure 2 very schematically illustrates this process, and shows how, for a photon arriving at A on the photo-cathode, the anode receives electrons on a rather large surface denoted D.
  • a dark enclosure 30 includes an internal partition 31 housing a converging lens 32. On both sides 'other of these are housed in the enclosure a photodiode 35 (point source of 0.5 mm) and a photomultiplier tube 36.
  • the photodiode is movable in a plane which is homologous with respect to the lens of the plane of the photocathode 37 of the tube 36. Thus the point image of the photodiode will be able to scan the entire surface of the photocathode.
  • the tube comprises several stages of dynodes 34 and an anode 33.
  • the tube 36 is for example the EMI 6262 model, conventionally polarized with a high voltage of 1500 volts.
  • a coil 39 produces a magnetic field oriented along the main axis 38 of the tube, for example downwards (the direction of the magnetic field has proven to be of little importance so far).
  • FIG. 4 illustrates on the ordinate the output signal of the tube on a logarithmic scale, as a function of the magnetic field applied, plotted linearly on the abscissa.
  • the photodiode has been placed in two positions corresponding to the two edges of one of the strips constituting the dynodes.
  • the points marked "+” and "o" correspond respectively to the lower and upper edges of the coverslip.
  • the gain is G O ;
  • the gain decreases, and the two points "+” and "o" separate more and more.
  • B 30 Gauss
  • the gain remains substantially constant.
  • the inventors estimated that the value of 30 Gauss corresponds to a radius of curvature of the electronic trajectories in the magnetic field of the order of magnitude of the width of the lamellae (3 mm).
  • the B field exceeds 30 Gauss, the radius of curvature of the trajectory of a secondary electron emitted by a dynode is small, and the electron is likely to be recaptured by the lamella, hence the rapid decrease in the gain with the magnetic field.
  • the field B is less than 30 Gauss, the electron has the greatest chances of gaining the following dynode, from where the gain appreciably constant.
  • FIG. 5 illustrates, for a magnetic field of 120 Gauss, the output signal of the tube plotted on the ordinate and on a logarithmic scale, as a function of the position of the light point on the cathode, plotted linearly on the abscissa.
  • This figure shows that the gain varies as a function of the position of the light source, and that the shape of the gain reflects the lamellar structure of the dynodes.
  • the inventors have also observed a channeling of the electronic trajectories around the axis of the field B. If we return to FIG. 3, the domain D becomes all the smaller as the field B is higher. Again, this is due to the radius of curvature imposed on the electronic trajectories by the magnetic field. This results in the possibility of locating at the level of the anode the origin A of the primary electron, by using for example a fractional or multi-anode anode.
  • the localization effect due to the magnetic field is acquired using the electron multiplier tube arranged according to FIG. 3.
  • this tube retains real multiplying properties, despite a gain less than the value G0 at zero field.
  • the simulation took into account the geometrical configuration of the tube, the value of the potentials between electrodes, the experimental data on the secondary emission of the dynodes, as well as the accessory effects. such as edge loss and space charge.
  • each dynode here comprises two levels.
  • the dynode D n-1 comprises the levels 61 and 62.
  • the level 61 comprises a series of strips or rather of elongated bars whose section is an isosceles right triangle of basic 0.5 mm.
  • the base is perpendicular to the main axis of the tube, and exposed to the next dynode.
  • the free space between the vertices of the bases of two adjacent bars is also 0.5 mm.
  • the second level 62 placed 2.5 mm from the first, is constituted in the same way, but its bars are aligned on the free spaces between those of the previous floor, so that seen from above the whole of the dynode constitutes a structure without free space.
  • the second dynode D n is similar to the first, its first level 63 being offset by 10 mm from level 61.
  • the surfaces active on the plane of the secondary electronic emission are at each level the two surfaces inclined at 45 °, defined by the sides of the right angle of the isosceles right triangle.
  • a voltage of 150 volts is established between the levels 61 and 62, a voltage of 600 volts between the stages 61 and 63, and again a voltage of 150 volts between the stages 63 and 64, the polarization being thus repeated periodically for the set of dynodes.
  • an electric field of 600 Volts / cm and a magnetic field of 400 Gauss such an electron multiplier is likely to reach a spatial resolution (at mid-height) of! 1.5 mm for a gain of the order of 10 7 .
  • Another structure, estimated to be less interesting because it is more complex, is illustrated in FIG. 7.
  • the concept of separate dynodes is diluted in this structure, because the set of dynodes consists of a large number of equidistant levels, such as 71 to 76 which are part of it.
  • Each level includes bars identical to those in Figure 6, but separated by a free space of 2.0 mm.
  • the bars of a given level are offset by 0.5 mm from those of the previous level, to the left for example.
  • the second level 76 bar is located vertically from the first level 71 bar, from the left.
  • the set of levels 71 to 75 forms an opaque system for an electron beam parallel to the z axis.
  • a dynode stage corresponds to 5 consecutive grids or levels, such as 71 to 75.
  • the pitch between stages is 12.5 mm.
  • a magnetic field of 410 Gauss, and a potential increasing by 400 Volts per stage, (ie an electric field of approximately 400 ' Volts / cm) is likely to reach a spatial resolution (halfway up the impact distribution on the anode) of t 1.5 mm, for a gain of the order of 10 7 .
  • the inventors have observed that the structures of dynodes whose bars have a section symmetrical with respect to the z axis are advantageous, as providing a better homogeneity of the field electric, and thereby better spatial resolution.
  • FIG. 8 Another structure of dynodes is illustrated in FIG. 8. Like that of FIG. 7, it has levels 81 to 86 of active elements regularly distributed along the axis Oz, and offset successively by a value equal to the small dimension. of these active elements, projected onto the x axis (0.5 mm); here again, the free space between two active elements is 2.0 mm, so that the active elements of level 86 are vertical to those of level 81. But, this time, instead of the bars with triangular section , the active elements are Venetian lamellae, inclined at 45 ° all on the same side, and of which only the face facing upwards is capable of secondary emission. A stage is again made up of 5 adjacent levels of lamellas, and the pitch between stages is 5 mm.
  • the secondary electrons thus produced must pass between the bars of the grid 62 to reach one or the other of the grids 63 and 64, and so on, taking into account the dimensions of the structure geometry. We will then say that the trajectories of the electrons coming from the grid 61 form a knot between the bars of the grid 62.
  • the two nodes are substantially aligned with the emission point in the z direction, and the electrons then have the greatest chance of touching the grid 76 or another of the consecutive grids forming the next stage, avoiding grids 72 to 75.
  • the trajectories are more complex, due to the poorer homogeneity of the electric field, due to the asymmetry of the lamellae with respect to the z axis.
  • trajectory nodes which we call here "helical focusing” is due to the relationship between the electric and magnetic fields, taking into account the geometry and the structure and its dimensions. It is this helical focusing which gives the property of localization of the electronic trajectories, that is to say the good spatial resolution in the xy plane. In this respect, it has been observed that if the electric and magnetic fields are multiplied jointly by a factor K, while dividing the dimensions of the structure and time by the same factor K, the equation of the electronic movement remains unchanged .
  • the spatial resolution can be all the better as the active elements of the grids are made finer, the electric and magnetic fields then being increased accordingly.
  • the electron multipliers according to the invention have better temporal resolution, than the photomultipliers of the louver type, their rise time being able to drop to less than 2 nanoseconds (10 to 90% of the current peak) against about 10 nanoseconds for most conventional Venetian dynode photomultipliers.
  • multiplicas Electrons are less prone to space charge problems in the upper stages than those of the prior art. Indeed, they have a better linearity of the gain as a function of the current of electrons, compared to photomultipliers with Venetian dynodes, if not those called "box-type".
  • the invention essentially provides an electron multiplier tube capable of localization, that is to say in which there is a fine correspondence between the points of departure of the electrons on the entry surface of the tube and the points of arrival. electrons on the exit surface of the tube.
  • the fineness of this correspondence is defined by the spatial resolution.
  • the currently preferred application is that of photomultipliers, the input surface then being a photocathode.
  • the invention can however be applied with all kinds of cathodes selectively emitting electrons on their surface (divided cathode for example). It is also possible to inject electrons produced by another source through the entry surface of the tube (electron accelerator for example).
  • electron-emitting surface here covers all of these situations.
  • the exit surface of the tube should of course allow selective detection of the electrons according to their point of arrival.
  • the simplest embodiment is an anode divided into fragments, provided with electrical connections. individual.
  • the resolution is independent of the statistical fluctuation due to the quantum efficiency of the photocathode, since the source of phototelectrons is common for all the adjacent anode fragments.
  • the resolution is therefore practically independent of the light intensity of the source analyzed.
  • the electroluminescent screen analogous to cathode ray tube screens, which allows visual and / or photographic examination.
  • the electron receiving surface can also be produced as in television shooting tubes, and include a mosaic of small elements which are charged by the effect of the received electrons, while a beam of analyzer electrons comes to scan this surface to read the charge of each element of the mosaic. A sequential signal is thus obtained which, linked to the scanning, defines the spatial distribution of the electrons received. Due to sequential scanning, this type of receiving surface does not fully benefit from the temporal resolution of the tube according to the invention.
  • the electron multiplier according to the invention is capable of numerous applications: direct detection of electrons, of photons (multi-photomultiplier), high gain image amplifier; the field of application is vast and includes in particular the detection of particles in nuclear physics and high energy physics, medicine, etc.
  • a photomultiplier according to the invention with a diameter of 100 mm could replace 50 to 100 small conventional photomultipliers with Venetian dynodes by offering excellent spatial resolution ( ⁇ 1.5 mm), a gain that is practically as good, more homogeneous and more linear, and higher time resolution.
  • each dynode stage is made up of several levels, offset between them so as to constitute together a practically opaque structure for the incident electrons.

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  • Electron Tubes For Measurement (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Measurement Of Radiation (AREA)
  • Microwave Tubes (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
  • Electron Sources, Ion Sources (AREA)
EP79401057A 1978-12-22 1979-12-21 Elektronenvervielfachungsvorrichtung mit axialem magnetischem Feld Expired EP0013235B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT79401057T ATE6711T1 (de) 1978-12-22 1979-12-21 Elektronenvervielfachungsvorrichtung mit axialem magnetischem feld.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7836148A FR2445018A1 (fr) 1978-12-22 1978-12-22 Tube multiplicateur d'electrons a champ magnetique axial
FR7836148 1978-12-22

Publications (2)

Publication Number Publication Date
EP0013235A1 true EP0013235A1 (de) 1980-07-09
EP0013235B1 EP0013235B1 (de) 1984-03-14

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EP79401057A Expired EP0013235B1 (de) 1978-12-22 1979-12-21 Elektronenvervielfachungsvorrichtung mit axialem magnetischem Feld

Country Status (6)

Country Link
US (1) US4339684A (de)
EP (1) EP0013235B1 (de)
JP (2) JPS5590047A (de)
AT (1) ATE6711T1 (de)
DE (1) DE2966814D1 (de)
FR (1) FR2445018A1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0165119A1 (de) * 1984-05-09 1985-12-18 ANVAR Agence Nationale de Valorisation de la Recherche Elektronenvervielfachervorrichtung mit Lokalisierung des elektrischen Feldes
US7731986B2 (en) 2003-11-17 2010-06-08 Btg International Ltd. Therapeutic foam
US8048439B2 (en) 2003-11-17 2011-11-01 Btg International Ltd. Therapeutic foam

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3709298A1 (de) * 1987-03-20 1988-09-29 Kernforschungsz Karlsruhe Micro-sekundaerelektronenvervielfacher und verfahren zu seiner herstellung

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR800440A (fr) * 1935-01-08 1936-07-04 Amplificateur électronique
US2115155A (en) * 1936-10-21 1938-04-26 Rca Corp Electron multiplier
FR827731A (fr) * 1936-10-21 1938-05-03 Marconi Wireless Telegraph Co Perfectionnements aux dispositifs à décharge électronique
FR49655E (fr) * 1936-11-20 1939-05-30 Electrical Res Prod Inc Appareil de décharge d'électrons
US2249016A (en) * 1937-11-24 1941-07-15 Emi Ltd Electron multiplying electrode
US2305179A (en) * 1938-05-27 1942-12-15 Emi Ltd Electron multiplier
US2712738A (en) * 1952-01-10 1955-07-12 Linde S Eismaschinen Ag Method for fractionating air by liquefaction and rectification
US3114044A (en) * 1959-09-30 1963-12-10 Westinghouse Electric Corp Electron multiplier isolating electrode structure
US3197662A (en) * 1960-03-11 1965-07-27 Westinghouse Electric Corp Transmissive spongy secondary emitter

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2172738A (en) * 1936-02-03 1939-09-12 Cathode ray tube
US2196278A (en) * 1937-08-31 1940-04-09 Bell Telephone Labor Inc Electron discharge apparatus
GB504927A (en) * 1937-10-28 1939-04-28 James Dwyer Mcgee Improvements in or relating to electron permeable electrodes
GB902090A (en) * 1957-11-12 1962-07-25 Emi Ltd Improvements in or relating to electron discharge devices
GB976619A (en) * 1960-03-05 1964-12-02 Emi Ltd Improvements in or relating to photo-emissive devices
US3191086A (en) * 1960-11-23 1965-06-22 Radames K H Gebel Secondary emission multiplier intensifier image orthicon
GB1470162A (en) * 1973-02-27 1977-04-14 Emi Ltd Electron multiplying arrangements

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR800440A (fr) * 1935-01-08 1936-07-04 Amplificateur électronique
US2115155A (en) * 1936-10-21 1938-04-26 Rca Corp Electron multiplier
FR827731A (fr) * 1936-10-21 1938-05-03 Marconi Wireless Telegraph Co Perfectionnements aux dispositifs à décharge électronique
FR49655E (fr) * 1936-11-20 1939-05-30 Electrical Res Prod Inc Appareil de décharge d'électrons
US2249016A (en) * 1937-11-24 1941-07-15 Emi Ltd Electron multiplying electrode
US2305179A (en) * 1938-05-27 1942-12-15 Emi Ltd Electron multiplier
US2712738A (en) * 1952-01-10 1955-07-12 Linde S Eismaschinen Ag Method for fractionating air by liquefaction and rectification
US3114044A (en) * 1959-09-30 1963-12-10 Westinghouse Electric Corp Electron multiplier isolating electrode structure
US3197662A (en) * 1960-03-11 1965-07-27 Westinghouse Electric Corp Transmissive spongy secondary emitter

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0165119A1 (de) * 1984-05-09 1985-12-18 ANVAR Agence Nationale de Valorisation de la Recherche Elektronenvervielfachervorrichtung mit Lokalisierung des elektrischen Feldes
FR2566175A1 (fr) * 1984-05-09 1985-12-20 Anvar Dispositif multiplicateur d'electrons, a localisation par le champ electrique
US4914351A (en) * 1984-05-09 1990-04-03 Agence Nationale De Valorisation De La Recherche (Anvar) Electron multiplier device having electric field localization
US7731986B2 (en) 2003-11-17 2010-06-08 Btg International Ltd. Therapeutic foam
US7763269B2 (en) 2003-11-17 2010-07-27 Btg International Ltd. Therapeutic foam
US8048439B2 (en) 2003-11-17 2011-11-01 Btg International Ltd. Therapeutic foam
US8323677B2 (en) 2003-11-17 2012-12-04 Btg International Ltd. Therapeutic foam

Also Published As

Publication number Publication date
ATE6711T1 (de) 1984-03-15
US4339684A (en) 1982-07-13
JPH0231457B2 (de) 1990-07-13
JPH0413814B2 (de) 1992-03-10
EP0013235B1 (de) 1984-03-14
JPS5590047A (en) 1980-07-08
FR2445018B1 (de) 1982-02-26
DE2966814D1 (en) 1984-04-19
JPS6324537A (ja) 1988-02-01
FR2445018A1 (fr) 1980-07-18

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