Abstract: Image intensifier systems incorporating a microchannel plate (MCP) and methods for producing the same are disclosed. In some examples, a device is disclosed that includes a first substrate having a radiation-receiving first surface and an opposed second surface through which electromagnetic radiation is transmitted. A second substrate is coupled to the first substrate to define a vacuum cavity therebetween. An electron-emitting photocathode is disposed within the vacuum cavity for generating electrons from electromagnetic radiation transmitted through the second surface. A microchannel plate is disposed within the vacuum cavity and defines microchannels extending from an input end to an output end. Each of the microchannels is configured to generate electrons in response to an electron generated by the photocathode being received through the input end of the respective microchannel.

Abstract: Electron beam modulation in response to optical pump pulses applied to a sample is measured using SPAD elements. Individual detection events are used to form histograms of numbers of events in time bins associated with pump pulse timing. The histograms can be produced at a SPAD array, simplifying data transfer. In some examples, two SPAD arrays are stacked and a coincidence circuit discriminates signal events from noise events by determining corresponding events are detected within a predetermined time window.

Abstract: Disclosed herein is a photomultiplier comprising: an electron ejector; a detector; a substrate; and a first electrode in the substrate; a second electrode in the substrate; a third electrode in the substrate; wherein each of the first, second and third electrodes comprises a flat or curved surface at an angle to a normal direction of the substrate; wherein each of the first, second and third electrodes comprises a first end and a second end, the first end being closer to the electron ejector than the second end; wherein the first, second and third electrodes are spatially arranged such that the second ends of the first, second and third electrode are on a same plane, or such that a plane the second ends of the first and third electrodes are on crosses the second electrode.

Abstract: Disclosed herein is a photomultiplier comprising: an electron ejector; a detector; a substrate; and a first electrode in the substrate; a second electrode in the substrate; a third electrode in the substrate; wherein each of the first, second and third electrodes comprises a flat or curved surface at an angle to a normal direction of the substrate; wherein each of the first, second and third electrodes comprises a first end and a second end, the first end being closer to the electron ejector than the second end; wherein the first, second and third electrodes are spatially arranged such that the second ends of the first, second and third electrode are on a same plane, or such that a plane the second ends of the first and third electrodes are on crosses the second electrode.

Abstract: An enhanced electron amplifier structure includes a substrate configured to amplify a signal of an incident particle by causing a cascade of secondary electron emissions and an enhancement layer configured to increase a sensitivity of the substrate to the incident particle. The enhancement layer is provided on an upper surface of the substrate.

Abstract: In one embodiment of the present invention, an electronic device includes a first emitter/collector region and a second emitter/collector region disposed in a substrate. The first emitter/collector region has a first edge/tip, and the second emitter/collector region has a second edge/tip. A gap separates the first edge/tip from the second edge/tip. The first emitter/collector region, the second emitter/collector region, and the gap form a field emission device.

Abstract: The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Abstract: The photomultiplier tube 1 is provided with an upper frame 2 and a lower frame 4 which are arranged so as to oppose each other, with the respective opposing surfaces 20a, 40a made with an insulating material, a side wall part 3 which constitutes a casing together with the frames 2, 4, a plurality of stages of electron multiplying parts 33 which are arrayed so as to be spaced away sequentially from a first end side to a second end side on the opposing surface 40a of the lower frame 4, a photocathode 41 which is installed on the first end side so as to be spaced away from the electron multiplying parts 33, converting incident light from outside to photoelectrons, an anode part 34 which is installed on the second end side so as to be spaced away from the electron multiplying parts 33 to take out electrons multiplied by the electron multiplying parts 33 as a signal, and a wall-like electrode 32 which is arranged so as to enclose the photocathode 41 when viewed from a direction directly opposite to an opposing sur

Abstract: The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Abstract: The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Abstract: The present invention relates to a photomultiplier having a fine configuration capable of realizing stable detection accuracy. The photomultiplier has a housing whose inside is maintained vacuum, and a photocathode, an electron-multiplier section, and an anode are disposed in the housing. In particular, one or more control electrodes disposed in an internal space of the housing which surrounds the electron-multiplier section and the anode are electrically connected via one or more connection parts extending from an electron emission terminal of the electron-multiplier section.

Abstract: An electron multiplier that can easily obtain characteristics according to a purpose is provided. By bonding a marginal portion 23 of an MCP 2 and a marginal portion 33 of an MCP 3 to each other via a conductive spacer layer 7, a gap 12 is formed between channel portions 22, 32. Therefore, when the electron multiplier is used for a purpose that requires a particularly high gain, by adjusting the thickness of the spacer layer 7, the gain can be increased by increasing the gap 12. In addition, when the electron multiplier is used for a purpose that requires an increase in gain as well as time characteristics, by adjusting the thickness of the spacer layer 7, the size of the gap 12 can be adjusted so that desired characteristics are obtained. Consequently, by only adjusting the thickness of the spacer layer 7, characteristics according to the purpose can be easily obtained.

Abstract: An ion detector includes collision surfaces for converting both positively and negatively charged ions into emitted secondary electrons. Secondary electrons may be detected using an electron detector, than may, for example include an electron multiplier. Conveniently, secondary electrons (or electrons emitted by the multiplier) may be detected using an electron pulse counter.

Abstract: A system for detecting ions is disclosed. The system includes a detector having a plurality of dynodes arranged in an electron cascading configuration, and a power supply circuit electrically coupled to the plurality of dynodes. The plurality of dynodes include a first dynode and a second dynode. The power supply circuit is arranged to selectively adjust a potential difference between the first and second dynodes between a detection mode and a blanking mode. A method of detecting ions is also disclosed.

Abstract: The present invention relates to a photomultiplier that realizes significant improvement of response time properties with a structure enabling mass production. The photomultiplier comprises an electron multiplier section for cascade-multiplying photoelectrons emitted from said photocathode. The electron multiplier has a structure holding at least two dynode sets while sandwiching the tube axis of a sealed container in this the electron multiplier is housed. In particular, the first dynodes respectively belonging to the two dynode sets are arranged such that their back surfaces opposing respective secondary electron emitting surfaces face each other while sandwiching the tube axis. In this arrangement, because each first dynode itself is positioned near the tube axis, the efficiency of collection of photoelectrons arriving at the periphery of the first dynode is improved significantly.

Abstract: Apparatus for amplifying a stream of primary charged particles comprises a body defining a chamber and an entrance aperture for receiving the stream of primary charged particles into the chamber, and an incident dynode, adapted to be charged to a pre-determined electrical potential, having a surface positioned in the chamber to be impacted by said primary charged particles at an angle of incidence greater than 30° from the surface normal and in response to the impact to generate a stream of secondary charged particles.

Abstract: A logical operation element and logical operation circuit are provided that are capable of high speed and a high degree of integration. A logical operation circuit has a construction wherein, in a logical operation element, the anodes of first and second field emission type microfabricated electron emitters are put at the same potential and two or more signal voltages are input to gate electrodes corresponding to these emitters. A NOR element so arranged that when a high potential input signal is input to either of the two lines, electron emission occurs from the emitters and the potential of said anodes is lowered, and a NAND element wherein the cathodes of the first and second field emission type microfabricated electron emitters are connected in series, two signal voltages are applied to the gate electrodes corresponding to the first and second emitter and the anode potential of the second emitter is lowered when the two input signals are high potential are employed.

Abstract: A time-resolved measurement apparatus (100) acquires a detection timing pulse from an output terminal (34) attached to a micro channel plate (30) in a photomultiplier tube (14). A position-time measuring circuit (16) generates a signal indicating the time difference between a reference time pulse synchronized with excitation of a sample (10) and the detection timing pulse, and feeds the signal to a data processor (18). The data processor stores this time difference as a detection time of light emission. The data processor corrects the detection time according to the distance between the position at which the detection timing pulse is generated on the micro channel plate and the output terminal. This enhances the precision of time-resolved measurement.

Abstract: A multi-purpose efficient charge particle detector that by switching bias voltages measures either secondary ions, or secondary electrons (SE) from a sample, or secondary electrons that originate from back scattered electrons (SE3), is described. The basic version of the detector structure and two stripped down versions enable its use for the following detection combinations: The major version is for measuring secondary ions, or secondary electrons from the sample, or secondary electrons due to back-scattered electrons that hit parts other than the sample together or without secondary electrons from the sample. Measuring secondary ions or secondary electrons from the sample (no SE3). Measuring secondary electrons from the sample and/or secondary electrons resulting from back-scattered electrons hitting objects other than the sample (no ions).

Abstract: In a photomultiplier tube (PMT) device having a plurality of dynodes provided between a cathode and an anode, a cancellation circuit provides two different modulation signals to the PMT to cancel the effects of the modulation signals upon the output of the PMT. For one embodiment, a cancellation circuit includes an input to receive an input modulation signal, a first output to provide a first output modulation signal to a first dynode, and a second output to provide a second output modulation signal to a second dynode, wherein the first and second output modulation signals are 180 degrees out-of-phase. For another embodiment, the cancellation circuit provides the input modulation signal to one of the PMT's dynodes, and also subtracts the input modulation signal from the PMT's output signal.

Abstract: A multiple electron beam source comprises a photon source to generate a photon beam, a lens to focus the photon beam, a photocathode having a photon receiving surface and an electron emitting surface, and an array of electron transmission gates spaced apart from the electron emitting surface of the photocathode by a distance dg. In one version, the multiple electron beam source comprises a photocathode stage assembly to move the photocathode relative to the array of electron transmission gates. In one version, the multiple electron beam source also comprises a plasmon-generating photon transmission plate comprising an array of photon transmission apertures and exterior surfaces capable of supporting plasmons.

Abstract: Primary electrons impinge upon an emitter section of an electron emitter for causing emission of the secondary electrons. The secondary electrons are outputted from the electron emitter. The secondary electrons emitted from the emitter section are accelerated in an electric field applied to the emitter section for generating an electron beam. The electron emitter has the emitter section having a plate shape, a cathode electrode formed on a front surface of the emitter section, an anode electrode formed on a back surface of the emitter section. A drive voltage from a pulse generation source is applied between the cathode electrode and the anode electrode through a resistor. The anode electrode is connected to GND. A collector electrode is provided above the cathode electrode. A bias voltage is applied to the collector electrode.

Abstract: An electron gun. The electron gun includes an RF cavity having a first side with an emitting surface and a second side with a transmitting and emitting section. The gun also includes a mechanism for producing an oscillating force which encompasses the emitting surface and the section so electrons are directed between the emitting surface and the section to contact the emitting surface and generate additional electrons and to contact the section to generate additional electrons or escape the cavity through the section. A method for producing electrons.

Abstract: In a photomultiplier, a ring-like side tube is not interposed between a side tube and a stem in the radial direction, and the side tube is joined to the ring-like side tube in a state of being directly capped onto a portion of the stem that protrudes out from an open end face at the upper side of the ring-like side tube. The enlargement of the photomultiplier in the radial direction due to overlapping of the side tube and the ring-like side tube can thereby be restricted and a high density, a high degree of integration, etc., can be realized in mounting the photomultiplier.

Abstract: Photomultiplier tubes with improved collection of incident radiation, especially from the periphery of the front face of the tube, and that more efficiently couple the collected radiation to the photocathode, and moreover have higher packing densities when assembled into arrays, resulting in enhanced imaging characteristics. The improvements in radiation collection and photomultiplier tube packing density are gained by a combination of several features including: tapering the edges of the faceplate so that the faceplate subtends an area as large or larger than any other cross-sectional area of the photomultiplier tube; forming the junction between the faceplate and metal tube on the underside of the faceplate, and in such a manner as to avoid obscuring the optical path between the incident radiation and photocathode; and utilizing the tapered edge of the faceplate as a reflector to couple radiation incident on the periphery of the faceplate to the photocathode.

Abstract: This invention provides a photodetector for weak light and a weak light detection system including the photodetector for weak light the photodetector for weak light is comprised of a substrate on which an integrating read circuit including a PIN photodiode or an APD and an FET is mounted, wherein the entire assembly is mounted while separating the substrate from a ground potential without grounding the substrate, such a photodetector for weak light can reduce noise and ensure a high enough sensitivity enough to be able to discriminate the number of photons.

Abstract: A faceplate (F) for an image intensifier tube (10) for reducing veiling glare begins as a blank (36) of optical material of a desired glass composition having a shape that conforms substantially to a configuration of the faceplate (F) to be produced. An extraneous removable aperture step portion (54) is formed on the glass blank (36). The glass blank is blackened (41) and the aperture step portion (54) is removed creating a desired transmissive aperture (34) through the glass blank (36).

Abstract: Electron focussing apparatus includes a cathode plate defining an impact surface on which particles impact, which surface has a finite probability of generating at least one electron for each impacting particle having predetermined characteristics. The apparatus also has an electron receiving element, and respective means for generating electrostatic and magnetic fields in a space extending from the impact surface to the electron receiving element. The means for generating the electrostatic and magnetic fields are configured whereby the E/B2 ratio adjacent the electron receiving element is smaller than adjacent the impact surface, whereby to decrease the radius of curvature of the electron trajectories adjacent the electron receiving element relative to adjacent the impact surface and to thereby focus the electron trajectories in at least one dimension.

Abstract: A replaceable, electronically-isolated, MCP-based spectrometer detector cartridge with enhanced sensitivity is disclosed. A mass detector is electro-optically isolated from a charge collector with an electron multiplier for converting a charged particle into a multiplicity of electrons and a scintillator for converting the multiplicity of electrons into a multiplicity of photons. A light sensor is provided to convert the multiplicity of photons back into electrons which are summed into a charge pulse. The light sensor is realized by any of a plurality of photo-responsive devices.

Abstract: A microchannel plate (P) for receiving photoelectrons includes a plate-like substrate web (W) formed from a plurality of micro-tubules (10) of a single type of cladding glass (12) and defining a pair of opposite faces (14a and 14b). The substrate web (W) further includes a plurality of microchannel passages (16) extending between the opposite faces (14a and 14b) and having openings (18a and 18b, respectively) in both of the opposite faces (14a and 14b). The microchannel openings (18) have funnel-like entries or openings (20) formed in the substrate web (W) with at least one of the opposite faces (14).

Abstract: An electron amplifier and a method of manufacturing the same are provided. The electron amplifier includes a substrate in which a plurality of through holes are formed, a resistive layer deposited on the sidewalls of the through holes, an electron emissive layer including carbon nanotubes which is deposited on the resistive layer, and an electrode layer formed on each of the upper and lower sides of the substrate. Because the electron emissive layer of the electron amplifier is uniform and provides a high electron emission efficiency, the electron amplification efficiency is improved. The electron amplifier manufacturing method enables economical mass production of electron amplifiers.

Abstract: A replaceable, electronically-isolated, MCP-based spectrometer detector cartridge with enhanced sensitivity is disclosed. A coating on the MCP that enhances the secondary electron emissivity characteristics of the MCP is selected from aluminum oxide (Al2O3), magnesium oxide (MgO), tin oxide (SnO2), quartz (SiO2), barium fluoride (BaF2), rubidium tin (Rb3Sn), beryllium oxide (BeO), diamond and combinations thereof A mass detector is electro-optically isolated the from a charge collector with a method of detecting a particle including accelerating the particle with a voltage, converting the particle into a multiplicity of electrons and converting the multiplicity of electrons into a multiplicity of photons. The photons then are converted back into electrons which are summed into a charge pulse. A detector also is provided.

Abstract: A photocathode and an electron tube in which the photocathode plate can be securely fixed without using any adhesive. Even under the severe condition that a high vibration resistance is required or thermal stress occurs because of great temperature variation, it can be used widely for an image intensifier, a streak tube, or a photomultiplier. The photocathode plate of the photocathode is sandwiched between a faceplate and a support plate. First pins embedded in the faceplate are joined to the support plate. Therefore, the photocathode plate can be readily fixed securely to the faceplate without using any adhesive.

Abstract: An electron multiplier includes a plate having a plurality of interconnected particles, e.g., fibers, having electron-emissive surfaces. The particles may include a neutron-sensitive and/or neutron reactive material, such as 6Li, 10B, 155Gd, 157Gd,—and/or hydrogenous compounds, in excess of their natural abundance. The particles may include an X-ray sensitive and/or X-ray reactive material, such as Pb.

Abstract: An electron gun that generate an electron flow and the application of this gun to produce rf energy or for injectors. The electron gun includes an electrostatic cavity having a first stage with emitting faces and multiple stages with emitting sections. The gun also includes a mechanism for producing an electrostatic force which encompasses the emitting faces and the multiple emitting sections so electrons are directed from the emitting faces toward the emitting sections to contact the emitting sections and generate additional electrons and to further contact other emitting sections to generate additional electrons and so on then finally to escape the end of the cavity. A method for producing a flow of electrons.

Abstract: An electron gun that generates multiple electron bunches and the application of this gun to produce rf energy. The electron gun includes an rf input cavity having a first side with multiple emitting surfaces and a second side with multiple transmitting and emitting sections. The gun also includes a mechanism for producing a rotating and oscillating force which encompasses the multiple emitting surfaces and the multiple sections so electrons are directed between the multiple emitting surfaces and the multiple sections to contact the multiple emitting surfaces and generate additional electrons and to contact the multiple sections to generate additional electrons or escape the cavity through the multiple sections. A method for producing multiple electron bunches.

Abstract: A charged particle beam method and apparatus use a primary electron beam to irradiate a specimen so as to induce the specimen to emit secondary and backscattered electrons carrying information about topographic and material structure of the specimen, respectively. The specimen may be an article to be inspected. The electrons emitted by the specimen are deflected in the electric field of an electron mirror and detected using an electron detector of the apparatus. The electron mirror permits the detection of the secondary electrons traveling close to the optical axis of the apparatus and corrects the aberrations of the secondary electrons. In addition, the electron mirror accelerates the electrons improving the detection efficiency of the electron detector and enhancing the time-of-flight dispersion characteristics of the secondary electron collection. A second electron mirror can be provided to further control the direction of the electron's landing on the surface of the electron detector.

Abstract: There is disclosed a three draw technique for drawing optical fibers into various cross-sectional shapes. The process employs a glass tube and rod which are fed into a heated furnace. The viscosity of the glass decreases and the glass flows. The glass is pulled or drawn out of the furnace at a different rate than it is fed into the furnace. The resultant drawn fibers are stacked and the process is repeated two more times. By employing three drawing steps one can achieve extremely small fiber faces. The final draw step uses a hexagonal cross-section preform and fibers. From the first drawn fibers three geometrical shapes can be assembled and finally drawn into hexagonal shapes with round fibers which are triangles, rhombohedrials and half hex or trapezoidal shapes. These shapes maintain the hexagonal closely packed space providing the highest density per cross-section. With this high density there is less glass flowing to fill voids thereby reducing distortion within the fabricated MCP.

Abstract: A particle and photon detector includes a body having a beam-incident surface (8) capable of releasing secondary electrons in numbers proportional to the number of particles incident on the surface, and a plurality of secondary electron multiplier channels (4) whose inlet openings are disposed in the beam-incident surface, therewith to amplify the number of secondary electrons. A center channel (2) extends from the beam-incident surface (8) through the detector body and enables a beam of particles or photons to pass through the body. The inlet openings of the secondary electron multipliers are conveniently disposed in the beam-incident surface in a ring around the center channel for receiving secondary electrons.

Abstract: A method for fabricating an electron multiplier is provided. The method consists of depositing a random channel layer on a substrate such that the random channel layer is capable of producing a cascade secondary electron emission in response to an incident electron in the presence of an electric field.

Abstract: According to the photomultiplier tube, the dynode unit 10 is constructed from a plurality of stages of dynodes 11 laminated one on another for multiplying incident electrons in a cascade manner through each of a plurality of channels. The anode unit 13 has a plurality of anodes 24 which define a plurality of electron passage gaps 14 each for transmitting the electrons emitted from the dynode unit 10 at a corresponding channel. The inverting dynode plate 15 is provided with a plurality of electron incident strips 17 each for receiving electrons having passed through a corresponding electron passage gap 14 in the anode unit 13, multiplying the electrons, and guiding the electrons back to the corresponding anode 24.

Abstract: A photomultiplier is constituted by a photocathode and an electron multiplier having a typical structure in which a dynode unit having a plurality of dynode plates stacked in an incident direction of photoelectrons, an anode plate, and an inverting dynode plate are sequentially stacked. Through holes for injecting a metal vapor are formed in the inverting dynode plate to form secondary electron emitting layers on the surfaces of dynodes supported by the dynode plates, and the photocathode. With this structure, the secondary electron emitting layers are uniformly formed on the surfaces of the dynodes. Therefore, variations in output signals obtained from anodes can be reduced regardless of the positions of the photocathode.

Abstract: A secondary electron emitter is provided and includes a substrate with a diamond film, the diamond film is treated or coated with an alkali-halide.

Abstract: A flat display apparatus has a substrate, a plurality of pointed cathodes formed on the substrate, a planar anode facing toward the cathodes via a vacuum space, and a light emitting layer on the side of the anode which is opposite from the cathodes. The anode has a plurality of projections in positions corresponding to the cathodes. The anode projections reduce electron scatter to improve light emission from the light emitting layer. In another embodiment of the flat display apparatus, a primary electron source and a plurality of secondary electron sources connected to bias voltages are disposed on the substrate and positioned relative to one another in an alternately staggered vertical positional sequence toward a light emitting member so that electrons are successively amplified.

Abstract: A flat display apparatus has a substrate, a plurality of pointed cathodes formed on the substrate, a planar anode facing toward the cathodes via a vacuum space, and a light emitting layer on the side of the anode which is opposite from the cathodes. The anode has a plurality of projections in positions corresponding to the cathodes. The anode projections reduce electron scatter to improve light emission from the light emitting layer. In another embodiment of the flat display apparatus, a plurality of electron sources are disposed on the substrate and positioned relative to one another in an alternately staggered vertical positional sequence toward a light emitting member so that electrons are successively amplified.

Abstract: A continuous thin film dynode includes a substrate with at least one channel having a channel wall, an isolation layer overlying the channel wall, and a thin film overlying the isolation layer. The thin film includes a current carrying portion and an electron emissive portion overlying the current carrying portion. The electron emissive portion is essentially free of a material which is silica-rich, alkali-rich, and lead-poor. The current carrying portion is essentially free of a material which is lead-rich.

Abstract: A series of improved electron multipliers is shown which are capable of reducing the number of bombardments per unit area. In the preferred embodiment, the inner channel is significantly increased in surface area over that surface area of present-day multipliers. Because the surface area is increased, for the same charge throughout, the number of electron bombardments per unit area is decreased. Since the number of bombardments per unit area is reduced, there is less degradation on the inner surface of the channel and hence the device lifetime is also increased.

Abstract: An electron multiplier tube including a grid type of plural dynode arrays arranged in a first direction with a multistage structure for successively multiplying electrons incident thereto and an anode provided below the multistage structure of dynode arrays for collecting the multiplied electrons to output an amplified electrical signal, each of the dynode arrays including plural rod-shaped dynode elements arranged in a second direction and a mesh electrode provided over each of the dynode arrays for providing an equipotential, wherein the multistage structure of dynode arrays includes at least one group of neighboring dynode arrays whose dynode elements are arranged so as to be aligned with one another in the first direction without displacement. Each of the dynode elements has a substantially isosceles trapezoid section, both side legs of the trapezoid being slightly inwardly curved to effectively receive the incident electrons which have been emitted from a dynode array at an upper stage.

Abstract: A parallel plate electron multiplier employing active dynode surfaces in confronting spaced relationship for effecting electron multiplication between the input and the output thereof in the active dynode area. Electron multiplication occurs in response to an accelerating biasing field extending between the input and the output. Electrostatic elements laterally of the dynode area establish lateral biasing fields in a direction transverse of the dynodes for containing electrons in the dynode area and for attracting positively charged species away from the dynode area in order to reduce spurious signals.

Abstract: A photomultiplier tube (10) for the use in high collecting power is described having a photocathode (20), a first dynode (30) and a stackable-dynode multiplier device (40). According to the invention, the first dynode (30) is constituted by a sheet which extends parallel to the photocathode (20) and is provided with a feedthrough aperture (31), an extracting grid (32) being arranged between the photocathode (20) and the sheet, and the stackable-dynode multiplier device (40) is positioned opposite the aperture (30) in such a manner as to collect the secondary electrons (50) emitted by the first dynode (30) and passing through the feedthrough aperture (31).