Abstract: A photomultiplier tube enhanced in simplicity and flexibility of mounting, a photomultiplier tube unit enhanced in photomultiplier tube assembling efficiency when unitized, and a radiation detector enhanced in assembling efficiency for a plurality of photomultiplier tubes. The photomultiplier tube (1) has a hermetically sealed vessel (5) easily screw-fixed in a predetermined position due to screwing means (30) provided in the stem plate (4). As a result, the photomultiplier tube (1) can be very easily attached or detached so that even an unskilled person can mount the photomultiplier tube (1) easily and accurately in a predetermined position by screwing.

Abstract: A side tube includes a tube head, a funnel-shaped connection neck, and a tube main body, which are arranged along a tube axis and which are integrated together into the side tube. The size of a cross section of the tube head perpendicular to the tube axis is larger than the size of a cross section of the tube main body perpendicular to the tube axis. The radius of curvature of rounded corners of the tube head is smaller than the radius of curvature of rounded corners of the tube main body. The length of the tube head along the tube axis is shorter than the length of the tube main body along the tube axis. One surface of a faceplate is connected to the tube head. A photocathode is formed on the surface of the faceplate in its area located inside the tube head.

Abstract: An electron tube 10 is provided with: an MCP (electron multiplier) 14 which includes a multiplying portion 16 having a large number of microscopic holes for electron passage that can emit secondary electrons and a peripheral portion 18 that surrounds multiplying portion 16; and with a vacuum closed container 12 enclosing at least multiplying portion 16 of MCP 14. Thus, peripheral portion 18 of MCP 14 forms at least a portion of sidewalls 22 of vacuum closed container 12. Multiplying portion 16 is increased in size in this configuration in comparison with configurations having the same outer dimensions that accommodate the entirety of an MCP inside of vacuum closed container 12.

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 Photo-Multiplier Tube (PMT) base for supplying long-term stable power, gain control and output amplification to a PMT. The present PMT base integrates the circuitry required for the dynode stages of the PMT with an amplifying circuit that amplifies the PMT output signals without disturbing the stable power that is required by each of the dynode stages. In operation the PMT base is electrically and mechanically connected to a PMT. The circuits for the dynode stages primarily provide gain control for each dynode stage in the PMT. The amplifying circuit in the PMT base is electrically connected to a dynode, the anode or both a dynode and the anode of the PMT, from which the PMT output signal is received. A PMT high voltage divider supplies the power to the circuitry required for the dynode stages and the amplifying circuit in the PMT base. The PMT base can be replaceable and can replace PMT bases that do not have an integrated amplifier for the PMT output signal.

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: A photomultiplier tube has a side tube with a stem plate fixed on one end and a faceplate fixed on the other. The side tube is formed of metal, and at least the portion of the stem plate contacting the metal side tube is formed of metal. The side tube and stem plate are fused together by laser welding or electron beam welding to form an airtight vessel, such that the outer edge of the stem plate does not protrude further externally than the outer surface of the side tube.

Abstract: In a photomultiplier, focusing pieces of a focusing electrode are formed with sufficient height that the photocathode in the adjacent channels cannot be viewed from the first and second stage dynodes of each channel in order to prevent light reflected from the first and second stage dynodes from returning to the adjacent channels. This construction prevents the photocathode from emitting undesired electrons, thereby suppressing crosstalk. Further, by arranging condensing lenses on the outer surface of a light-receiving faceplate in correspondence with each channel, light is reliably condensed in each channel. Further, an oxide film formed. over the surface of the focusing pieces prevents the reflection of light off the focusing pieces.

Abstract: The present invention relates to an apparatus for detection of radiation comprising a photocathode layer adapted to release photoelectrons in dependence on incident radiation; a radiation entrance arranged such that a beam of radiation can be entered into the apparatus through said radiation entrance and can impinge on said photocathode layer at grazing incidence; an electron avalanche amplifier adapted to avalanche amplify photoelectrons released from said photocathode layer; and a readout arrangement adapted to detect avalanche amplified electrons from said amplifier. The invention further relates to a corresponding method for detection of ionizing radiation and to an arrangement for use in planar beam radiography comprising the detector apparatus.

Abstract: The cathode for photo-electron emission 5 is comprised of an alkali metal containing layer 5d made of material for emitting photo-electrons by the entry of light or for emitting secondary electrons by the entry of electrons, such as particles which consist of an alkali antimony compound, on an Ni electrode substrate 5c on which an Al layer 5b is deposited, and has an intermediate layer 5a made of carbon nano-tubes between the alkali metal containing layer 5d and the Ni electrode substrate 5c, therefore the defect density inside the particles is decreased, and the recombining probability of electrons and holes drops remarkably, which improves the quantum efficiency.

Abstract: To reduce the size of a photomultiplier tube (1), a side tube (2) is fixedly secured by welding to a stem plate (4) while an inner surface (2c) of the lower portion (2a) of the side tube (2) is maintained to be in contact with an outer edge (4b) of the stem plate (4). As a result, there is no projection like a flange at the lower portion of the photomultiplier tube (1). Therefore, though it is difficult to perform resistance welding, the outside dimensions of the photomultiplier tube (1) can be decreased, and the side tubes (9) can densely abut to one another even if the photomultiplier tubes (2) are arranged when applied. Hence, high-density arrangement of photomultiplier tubes (1) are realized by assembling metallic stem plate (4) and the side tube (2) by, for example, laser welding.

Abstract: In a photomultiplier tube 1, an etching technique is used to form electron multiplying holes 8a in plate-shaped dynodes 8 that are stacked in multiple layers. To perform this etching process, a pattern frame 22 is disposed around a plate-shaped dynode substrate 20. A bridge portion 23 is provided for connecting the pattern frame 22 to an edges 20a of the dynode substrate 20. The dynode substrate 20 is masked, and the etching process is performed to form a plurality of electron multiplying holes 8a in the dynode substrate 20. Subsequently, the bridge portion 23 is cut near the dynode substrate 20, leaving a small bridge remainder 8c on the edge 8b of the dynode 8.

Abstract: A photomultiplier tube excellent in vibration resistance and having an anode with good pulse linearity characteristic. The photomultiplier tube has a mesh anode (A) composed of an anode frame (A11) and a mesh electrode (A12) supported and surrounded by the anode frame (A11). The central portion of one long side (A11B) of the anode frame (A11) serves as an electron converging part (F). The inner side of the anode frame (A11) swells toward the inner part of the anode (A), more from the middle of the long side (A11B) toward the corners of the anode frame (A11) along the long side (A11B), and therefore the thickness of the anode frame (A11) increases from the middle of the long side (A11) to the corners along the long side (A11B).

Abstract: A photocathode having a UV glass substrate and a laminate composed of a SiO2 layer, a GaAlN layer, a Group III-V nitride semiconductor layer and an AlN buffer layer provided on the UV glass substrate in succession. The UV glass substrate, which absorbs infrared rays, can be heat treated at a high speed by photoheating. Further, the UV glass substrate, which is transparent to ultraviolet rays, permits ultraviolet rays to be introduced into the Group III-V nitride semiconductor layer where photoelectric conversion occurs.

Abstract: To prevent the deterioration in sensitivity of the photocathode (20) of an electron tube and maintain stable output for a long time, an ion confining electrode (22) and an ion trap electrode (23) are provided between the photocathode (20) and a first stage dynode (24a). The potential of the ion confining electrode (22) is set higher than that of the first stage dynode (24a), while the potential of the ion trap electrode (23) is set equal to or higher than that of the photocathode (20) and lower than that of the first stage dynode 24a. Since the feedback to the photocathode (20) of the positive ions generated in the vicinity of the first stage dynode can be effectively suppressed, the sensitivity of the photocathode (20) is prevented from decreasing, and stable output is maintained for a long time.

Abstract: In this photomultiplier tube 1, light incident on a light-receiving faceplate 3 is converted into photoelectrons by a photosensitive surface 3a, and the photoelectrons strike a dynode 4 to emit many secondary electrons. The secondary electrons are then collected by a mesh-like anode 5. Since the anode 5 is disposed to be parallel to the photosensitive surface 3a, the photoelectrons emerging from the photosensitive surface 3a can easily pass through a mesh portion 5a, and many photoelectrons can be made to strike the dynode 4. As the number of photoelectrons incident on the dynode 4 increases, the number of secondary electrons from the dynode 4 increases. This improves the gain characteristics of the photomultiplier tube 1. Since a secondary electron emission surface 4a of the dynode 4 is tilted with respect to the anode 5, photoelectrons having passed through the anode 5 obliquely strike the secondary electron emission surface 4a of the dynode 4.

Abstract: A cathode (5) for emitting photoelectrons or secondary electrons comprises a nickel electrode substrate (5c) with an aluminum layer (5b) deposited on it; an intermediate layer (5a) consisting of carbon nanotubes formed on the aluminum layer; and an alkaline metal layer (5d) formed on the intermediate layer (5a) and composed, for example, of particles of an alkali antimony compound that either emits photoelectrons in response to incident light or emits secondary electrons in response to incident electrons. The decrease in defect density of the particles reduces the probability of recombination of electron and hole remarkably, thus increasing quantum efficiency.

Abstract: A photomultiplier tube unit including photomultiplier tubes densely assembled and thereby having an improved light sensing efficiency. The outer surfaces (2b) of metal side tubes (2) of photomultiplier tubes (1) are in facial contact with one another, and thereby a high-density arrangement of photomultiplier tubes (1) are achieved. The side tubes (2) can be electrically connected to one another, and therefore the side tubes (2) can be easily made equipotential. As a result, it is unnecessary to electrically connect the stem pin (10) to the side tube (2) of each photomultiplier tube (1), facilitating the assembling of the photomultiplier tube unit. When a required photomultiplier tube (1) in a device (e.g., a gamma camera) having thus-united multiple photomultiplier tubes is replaced with a new one, the troublesome work of replacing photomultiplier tubes one by one is obviated, simplifying the replacement work.

Abstract: A photomultiplier tube includes dynodes electrically joined to corresponding leads. The tube, containing a loose debris particle, may be reprocessed by positioning the particle at an accessible site inside the tube. A power laser is aimed at the particle through a transparent wall of the tube and fired to reduce the size of the particle.

Abstract: A photomultiplier tube includes a photocathode and a primary dynode having input and output apertures. A field isolating mesh is positioned at the input aperture of the primary dynode to facilitate the collection of electrons from the photocathode of the photomultiplier to the primary dynode while simultaneously electrostatically shielding secondary emission electrons from the field of the photocathode. The field isolating mesh has a central opening that is dimensioned to maximize the throughput of photoelectrons from the photocathode to the primary dynode while providing effective field isolation in the vicinity of the primary dynode. The central opening in the field isolation mesh provides the further advantage of permitting uniform deposition of photo-emissive materials on the surface of the dynode during manufacture. In an alternative embodiment, the field isolating mesh of the primary dynode is formed in two segments.

Abstract: An electron multiplication apparatus uses a matrix of dielectric particles interspersed with conductive particles. Typically a porous layer of metal oxide and relatively inert metal, the material provides high electron count rates while maintaining good temperature stability. The layer is located between a cathode and an anode that together provide desired voltage differentials. A mesh is also used on a side of the matrix layer opposite the cathode to conduct surface charge away from the matrix, while providing an intermediate voltage potential between that of the anode and the cathode. A voltage source is used to generate the voltage potentials for each of the anode, cathode and mesh layer, and the resulting electric fields provide a device that may be used in the detection of high energy particles and photons, such as x-rays. A preferred method of fabricating the material involves the codeposition of a metal prone to oxidation and a relatively inert metal to form a porous layer.

Abstract: The present invention provides an X-ray image detector (1) which can reduce the size of a whole apparatus associated with an X-ray imaging tube, reduce noise components of an output X-ray image even if an incident X-ray is very weak, and provide a distortion-free visible image or electric image.

Abstract: An image intensifier tube includes a photocathode (20) with an active layer (52) providing an electrical spectral response to photons of light. The photocathode (20) also includes integral spacer structure (42) which extends toward and physically touches a microchannel plate (22) of the image intensifier tube in order to establish and maintain a desirably precise and fine-dimension spacing distance “G” between the photocathode and the microchannel plate. A method of making the photocathode and a method of making the image intensifier tube are described also.

Abstract: An X-ray image tube according to the present invention has a whole evacuated envelope comprising an metallic input window through which X-rays pass, a metallic frame to which the metallic input window is welded, a hollow cylinder portion, an output window, etc., and the metallic input window and the metallic frame are hermetically welded to each other by ultrasonic welding. By means of such a construction, an X-ray image tube which can suppress occurrence of distortion of an electronic lens formed in the evacuated envelope, and a manufacturing method thereof is realized.

Abstract: This invention relates to an electron tube having a structure for enabling a stable operation for a long time. In the electron tube, at least a confining mechanism is arranged between a photocathode and the electron incident surface of a semiconductor device, which are arranged to oppose each other. In the arrangement, the area of the opening of the confining mechanism is at least equal to or smaller than that of the electron incident surface, thereby confining the orbits of photoelectrons from the photocathode. This structure avoids bombardment of electrons arriving at portions other than the electron incident surface of the semiconductor device and prevents the semiconductor device from being unnecessarily charged.

Abstract: An electronic circuit for use in a monocular night vision device for electronically controlling a plurality of components within the device, the device having an objective lens assembly for receiving low intensity light, a variable gain image intensifier tube having a user adjustable variable gain controller external to the tube for adjusting the light intensity level of a visible output image, a single eyepiece lens assembly for viewing the output image from the image intensifier assembly; and a non-metallic housing comprising an upper housing for receiving the objective lens assembly, image intensifier assembly, and eyepiece lens assembly, and a lower housing containing a battery cavity for receiving batteries to power the device. The housing aligns the objective lens assembly with the image intensifier assembly and the eyepiece lens assembly along an optical axis wherein the upper and lower housing are coupled to one another along the optical axis.

Abstract: The present invention relates to an electron multiplier including a structure which effectively prevents an electric field from leaking to the front side of an MCP due to a voltage applied to the MCP, facilitates an operation of attaching/detaching the MCP, and prevents the MCP from being damaged and so forth during the operation. The electron multiplier includes an MCP as electron multiplying means, and an outer electric field shield member for accommodating the MCP. The electric field shield cap includes a body portion surrounding at least a side face of the MCP. The electron multiplier further includes a structure by which, while the MCP is held by the outer electric field shield member and an inner electric field shield member accommodated in the outer electric field shield member, the outer electric field shield member is attached to a base of the electron multiplier so as to facilitate the operation of attaching/detaching the MCP.

Abstract: An electron multiplier with a source for spontaneously generating electrons is used as an electron source for an ionization source in a mass spectrometer or the like. The electron multiplier can be a microchannel plate, in which case it produces a wide electron beam. The microchannel plate can be acid-leached to provide a surface for spontaneous generation of electrons, or the first strike surface can be coated with an alkali-containing material. The electron source can be tuned by providing an electrode for rejecting electrons having too high an energy and a grid for rejecting electrons having too low an energy.

Abstract: The present invention relates to an electron tube comprising, at least, a cathode electrode, a face plate having a photocathode, and an electron entrance surface provided at a position where the electron emitted from the photocathode reaches. The object of the present invention is to provide an electron tube which can reduce its size and has a structure for improving the workability in its assembling process. In particular, the electron tube according to the present invention has a bonding ring, provided between the face plate and the cathode electrode, for bonding the face plate and the cathode electrode together. The bonding ring is made of a metal material selected from the group consisting of In, Au, Pb, alloys containing In, and alloys containing Pb.

Abstract: To provide an electron tube having good airtightness and being appropriate for mass production, indium affixed to the inner surface of a sealing metal support member is provided between a side tube and input faceplate. The input faceplate is pushed against the side tube. As a result, the indium is squeezed by a pressure receiving surface provided on the end face of the side tube. Since the pressure receiving surface is in a generally declining shape from the inside out, the force of the pressing surface causes the indium to flow outward toward the sealing metal support member. Therefore, the indium is firmly affixed to the pressure receiving surface, and the side tube and input faceplate can be reliably sealed by the indium.

Abstract: An electron tube in which a side tube and a faceplate are sealed together using a malleable metal with a low melting point. The metal is made to spread out along the outer surface of the faceplate due to pressure from a first sealing portion of a sealing metal support member and along the peripheral surface of the electron tube due to pressure from a second sealing portion of the sealing metal support member. Accordingly, the outer side of the corner portion formed by the faceplate and the side tube is covered with the metal. This construction not only reliably secures the input faceplate to the side tube, but also is extremely effective in preserving the airtightness of the electron tube. Since the first sealing portion is pressed toward the faceplate, an appropriate pressure can be applied to the metal interposed between the first sealing portion and the faceplate, improving the sealability of the metal against the faceplate and the first sealing portion.

Abstract: The present invention relates to a photocathode having a structure for improving the quantum efficiency and sharpening the absorption edge characteristic on the long wavelength side within the wavelength range of incident light to improve the photosensitivity, and an electron tube having the same. The photocathode according to the present invention comprises at least a p-type GaAlN layer for absorbing incident light to excite photoelectrons, a p-type GaN layer which covers the second major surface of the p-type GaAlN layer, the second major surface opposing a first major surface that faces a substrate, and a surface layer provided to sandwich the p-type GaN layer with the p-type GaAlN layer and mainly containing an alkali metal or an alkali metal oxide.

Abstract: This detector comprises electron multiplication means (14) producing a cluster of electrons under the impact of each particle (2), a layer (6) that this cluster passes through, and which emits a light pulse by interaction with the layer, and transparent electron detection means (8) capable of determining the moment of impact of the particle and supplying information about the impact positions for each moment thus determined, so that these positions can be determined and correlated with the moments determined by the detection means.

Abstract: The present invention relates to a versatile side-on type photomultiplier comprising a structure for improving the uniformity in light receiving sensitivity. Disposed on the outer peripheral surface of a sealed envelope of this photomultiplier is a restricting member which guides light to be detected into, of the light receiving surface of a photocathode, an effective region where the light receiving sensitivity is high, thereby restraining the light to be detected from reaching the outside of the effective region.

Abstract: In the microchannel 50, a conductive film 52 is formed on an electron input surface of a dynode 51 where the plurality of channels are arranged. The conductive film is made of material that can transmit light that has originated photoelectrons and that has a refractive index lower than that of the dynode constituting material.

Abstract: This invention relates to an electron tube which stabilizes the orbits of electrons accelerated and focused by an electron lens and has a structure for effectively suppressing noise generated due to discharge. This electron tube has, at two ends of an insulating container, a cathode electrode and an anode electrode which constitute the electron lens. Particularly, in the electron tube, one end of the cathode electrode and a photocathode are supported by a conductive member arranged at one end of the insulating container, and the cathode electrode is electrically connected to the photocathode. The cathode electrode partially extends to a stem along the inner wall of the insulating container and is tapered toward the stem so that the distal end portion of the cathode electrode is separated from the inner wall of the insulating container.

Abstract: A photomultiplier tube of the present invention is the one which collects the electrons, which have been multiplied by the dynodes laminated into a plurality of stages in the electron multiplier section and that have subsequently been reflected at the final-stage dynode, as an output signal. The photomultiplier tube forms the final-stage dynode as multi-stage, for example, in two layers, and has its alkali metal vapor passage holes of its first layer so arranged as to have the holes shifted with respect to the alkali metal vapor passage holes of the second layer. Furthermore, each of the dynodes, except the final-stage dynode consists of the focusing mesh electrode, the coarse mesh electrode, and the spacer electrode and the reinforcing bars are formed at identical locations in the coarse mesh electrode and the spacer electrode. Secondary electron emission sections are provided in the vicinity regions of these reinforcing bars of the focusing mesh electrodes.

Abstract: The present invention relates to an electron tube includes, at least, a cathode electrode and a face plate having a photocathode which are arranged at one end of a body, and a stem arranged at the other end of the body for defining the position of an electron entrance surface where the electron emitted from the photocathode reaches. The object of the present invention is to provide an electron tube which can reduce its size and has a structure for improving the workability in its assembling process. In particular, the electron tube in accordance with the present invention comprises a bonding ring, provided between the face plate and the cathode electrode, for bonding the face plate and the cathode electrode together. The bonding ring is made of a metal material selected from the group consisting of In, Au, Pb, alloys containing In, and alloys containing Pb.

Abstract: In the photomultiplier tube 1, the focusing electrode plate 17 has the focusing portion 20 for focusing incident electrons and the frame 21 surrounding the focusing portion 20. The focusing portion 20 has a plurality of slit openings 18. The dynode unit 10 is constructed from a plurality of dynode plates 11 laminated one on another. Each dynode plate 11 has a plurality of electron through-holes 13 located in confrontation with the plurality of slit openings 18. A plurality of anodes 9 are provided for receiving electrons emitted from the respective through-holes 13 of the dynode unit 10. The frame 21 has dummy openings 22 at positions located in confrontation with edges 15 of the first stage dynode plate 11a in the dynode unit 10.

Abstract: This invention relates to an electron tube having a structure for enabling a stable operation for a long time. In the electron tube, at least a confining mechanism is arranged between a photocathode and the electron incident surface of a semiconductor device, which are arranged to oppose each other through a container. Particularly, the area of the opening of the confining mechanism is smaller than that of the electron incident surface, thereby confining the orbits of photoelectrons from the photocathode. This structure avoids bombardment of electrons arriving at portions other than the electron incident surface of the semiconductor device and prevents the semiconductor device from being unnecessarily charged.

Abstract: The present invention relates to a versatile side-on type photomultiplier comprising a structure for improving the uniformity in light receiving sensitivity. This photomultiplier comprises a positioning structure for precisely positioning, with respect to the light receiving surface of a photocathode, a lens element which guides light to be detected to a photocathode and constitutes a part of an envelope accommodating the photocathode. The precisely positioned lens element guides the light to be detected into, of the light receiving surface of the photocathode, an effective region where the light receiving sensitivity is high, thereby restraining the light to be detected from reaching the outside of the effective region.

Abstract: The present invention concerns a photomultiplier having a lamination structure of fine mesh dynodes arranged at predetermined intervals, capable of detecting photons even in a high magnetic field. This photomultiplier is arranged so that hollow pipes penetrating electrodes for supporting the fine mesh dynodes define the lamination structure of an electron multiplier unit. This arrangement permits the intervals between the fine mesh dynodes to be accurately controlled, thereby obtaining the photomultiplier production errors of which are well suppressed and preventing that the fine mesh dynodes are ripped.

Abstract: A photomultiplier of the present invention has an electron multiplier of a structure which can be manufactured easily. This electron multiplier is constituted by dynode plates that are stacked through insulators so as to be separated from each other at a predetermined interval. Each dynode plate comprises upper- and lower-electrode plates that are electrically connected to each other. The upper- and lower-electrode plates grip at least one of the insulators such that the gripped insulator is partly exposed.

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: An electron tube includes an electron multiplication unit for multiplying an incident electron flow by secondary electron emission. This electron multiplication unit is formed by stacking a plurality of dynodes toward an incident side of the electron flow. A plurality of through holes are arranged and formed in each dynode, in which one end on the incident side of the electron flow is used as an input opening, and the other end is used as an output opening. An acceleration electrode unit projecting toward the through hole of the upper dynode is provided at an edge portion of the input opening. As described above, the acceleration electrode unit is provided at the edge portion of the input opening of the through hole formed in each dynode. For this reason, a damping electric field is pushed up by the acceleration electrode unit and deeply warped into the through hole of the upper dynode.

Abstract: A luminous flux measuring device has a gain slaving circuit (10, 9), that receives an electrical output signal (m) produced by a photoreceiver (1) and includes a gain control circuit (9) and a comparator (10). The gain slaving circuit is connected to an A/D converter and a computer to record and evaluate the signal (m) and has a slave memory containing characteristic values (a,b) of a continuous function (f). The gain slaving circuit produces a slave signal (HT) according to the flux received (.PHI.) by the photoreceiver which signal is sent to the gain control circuit so that G=f(m).

Abstract: An electron multiplier of the perforated sheet type includes two successive sheets constituting a dynode which has several multiplier channels in common. For controlling the gain of a given channel (A), a control electrode (30) is provided in the form of a sheet inserted between the sheets (14, 15) of a dynode (Dn) which has a grating window (33) controlling the gain of the channel (A) in question, and one (or several) aperture(s) (34) in accordance with the number of remaining channels. Another channel (B) is controlled by another electrode (31) inserted between the sheets (16, 17) of another dynode (D.sub.n+1). Also disclosed is a multi-channel photomultiplier tube which includes such an electron multiplier.

Abstract: A photoelectric emission surface which is excellent in stability and reproducibility of photoelectric conversion characteristics and has a structure capable of obtaining a high photosensitivity is provided. A predetermined voltage is applied between an upper surface electrode and a lower surface electrode by a battery. Upon application of this voltage, a p-n junction formed between a contact layer and an electron emission layer is reversely biased. A depletion layer extends from the p-n junction into the photoelectric emission surface, and an electric field is formed in the electron emission layer and a light absorbing layer in a direction for accelerating photoelectrons. When incident light is absorbed in the light absorbing layer to excite photoelectrons, the photoelectrons are accelerated by the electric field toward the emission surface.

Abstract: An electron multiplier includes an improved resistor assembly for applying relevant voltages to respective dynodes. Resistor patterns are printed on one surface of an insulation substrate. Each resistor pattern is connected to one end of one of a plurality of conductor patterns which are also printed on the same surface of the insulation substrate, so that each resistor pattern is sandwiched between adjacent conductor patterns to provide a predetermined resistance therebetween. The other end of each conductor pattern extends to a corresponding insertion hole formed on the insulation substrate. One end of a conductor element, which may be a lead, wire, or other wire shaped conductor, is inserted into the corresponding insertion hole and electrically connected to its corresponding conductor pattern. At least the area around where the conductor pattern is connected to the conductor element and also areas around resistor patterns are covered with an insulating seal material.

Abstract: In a photomultiplier of the present invention, a semiconductor device arranged in an envelope to oppose a photocathode is constituted by a semiconductor substrate of a first conductivity type, a carrier multiplication layer of a second conductivity type different from the first conductivity type, which is formed on the semiconductor substrate by opitaxial growth, a breakdown voltage control layer of the second conductivity type, which is formed on the carrier multiplication layer and has a dopant concentration higher than that of the carrier multiplication layer, a first insulating layer formed on the breakdown voltage control layer and said carrier multiplication layer while partially exposing the surface of the breakdown voltage control layer as a receptor for photoelectrons and consisting of a nitride, and an ohmic electrode layer formed on a peripheral surface portion of the receptor of the breakdown voltage control layer.