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: Single-channel photomultiplier tube (1) having a sealed envelope (4), of which one wall (5) comprises an internal face (7) having a concavity with a central axis (AA?), turned toward the inside of the tube, having a plane of symmetry and containing a photocathode (2), inlet optics (9) comprising electrodes, an electron multiplier (11) comprising a plurality of dynodes (30-39), an anode (16), means (12) for connecting the dynodes (30-39), the photocathode (2), electrodes (13, 15) of the optics (9), and the anode (16), at their respective operating voltages, characterised in that the electron multiplier is composed of parts (24, 26) physically distinct from one another, and having between them a symmetry of revolution with respect to the central axis of concavity.

Abstract: The present invention relates to a photomultiplier having a structure that enables to perform high gain and satisfy higher required characteristics. In the photomultiplier, an electron-multiplying unit accommodated in a sealed container comprises a focusing electrode, an accelerating electrode, a dynode unit, and an anode. Particularly, at least the accelerating electrode and dynode unit are held unitedly in a state that at least a first-stage dynode and a second-stage included in the dynode unit are opposite directly to the accelerating electrode not through a conductive material. A conventional metal disk for supporting directly dynodes which are set to the same potential as that of the first-stage dynode is not placed between the accelerating electrode and dynode unit; thus, variations of the transit time of electrons may be drastically reduced while the electrons reach from the cathode to the second-stage dynode via the first-stage dynode.

Abstract: The present invention relates to a photomultiplier having a structure that enables to perform high gain and satisfy higher required characteristics. In the photomultiplier, an electron-multiplying unit accommodated in a sealed container comprises a focusing electrode, an accelerating electrode, a dynode unit, and an anode. Particularly, at least the accelerating electrode and dynode unit are held unitedly in a state that at least a first-stage dynode and a second-stage included in the dynode unit are opposite directly to the accelerating electrode not through a conductive material. A conventional metal disk for supporting directly dynodes which are set to the same potential as that of the first-stage dynode is not placed between the accelerating electrode and dynode unit; thus, variations of the transit time of electrons may be drastically reduced while the electrons reach from the cathode to the second-stage dynode via the first-stage dynode.

Abstract: The present invention relates to a photomultiplier having a structure for performing a high gain and achieving a higher productivity in a state keeping or improving an excellent high-speed response. In the photomultiplier, an electron-multiplying unit, placed in a sealed container, has a structure that enables an integrated assembly of a focusing electrode, an accelerating electrode, a dynode unit, and an anode. Specifically, by providing a structure for fixing directly the focusing electrode and accelerating electrode at a part of a pair of insulating support members for grasping directly the dynode unit and so on, together with the dynode unit and anode, each of the focusing electrode and accelerating electrode is aligned by using the pair of insulating support members as a reference.

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: The present invention relates to a photomultiplier that realizes significant improvement of response time properties with a structure enabling mass production. The photomultiplier comprises a sealed container, and, in the sealed container, a photocathode, at least one dynode set, a dynode unit including a part of insulating supporting members holding the one dynode unit, and a gain control unit are housed. The gain control unit has an insulating base plate, and the insulating base plate is integrally fixed with a control dynode and a final stage dynode that belong to each dynode set together with an anode. By the insulating base plate thus being clamped by the pair of insulating supporting members, the anode, the control dynode, and the final stage dynode constitute a part of an electron multiplier section.

Abstract: The present invention relates to a photomultiplier that realizes significant improvement of response time properties with a structure enabling mass production. In the sealed container, a photocathode, a dynode unit including at least one dynode set, and preferably dynode sets of two series, a focusing electrode unit arranged between the photocathode and the dynode unit are housed. The focusing electrode unit is set to the same potential as the second dynode arranged at a position where secondary electrons from said first dynode, which emits secondary electrons in response to incidence of photoelectrons, arrive, and is provided with partitioning plates partitioning the second dynode into two in a longitudinal direction of the second dynode.

Abstract: Therefore, use of the electron lens forming electrodes 115 and 117 flattens the potential distribution in the longitudinal direction of the first dynode 107a in front of the first dynode 107a, that is, between the dynodes 107a and 107b. As a result, both photoelectrons emitted from the peripheral edge of the cathode 3 and photoelectrons emitted from the center region of the cathode 3 travel substantially in a straight line from the first dynode 107a after being multiplied thereby to impinge on the second dynode 107b. Since this structure reduces deviation in the transit distance of photoelectrons based on the irradiated position of light on the cathode 3, the structure also reduces the cathode transit time difference (CTTD) according to the irradiated position of light and a transit time spread (TTS) when light is irradiated on the entire surface.

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: The present invention relates to a photodetector that has a structure capable of realizing a wide range gain adjustment for each of electron multiplier channels respectively assigned to a plurality of light incidence regions of a multi-anode multiplier. The photodetector comprises a multi-anode photomultiplier, and a bleeder circuit unit. The multi-anode multiplier has a dynode unit constituted by N (an integer or no less than 3) dynode plates, and n-th (an integer of no less then 2) dynode plate is constituted by a plurality of control plates respectively corresponding to the multiplier channels. The bleeder circuit unit has a primary section setting each potential of a first to (n?1)-th and (n+1)-th to N-th dynode plates, and a secondary section for individually setting a potential of each control plate at any potential within the range wider than a potential difference between the (n?1)-th and (n+1) dynode plates.

Abstract: The present invention relates to a photomultiplier having a structure for performing a high gain and achieving a higher productivity in a state keeping or improving an excellent high-speed response. In the photomultiplier, an electron-multiplying unit accommodated in a sealed container has a structure that enables an integrated assembly of a focusing electrode, an accelerating electrode, a dynode unit, and an anode. Specifically, the focusing electrode has one or more notched portions to be grasped by a part of each of the insulating support members for grasping directly the dynode unit and so on when the focusing electrode itself is rotated around the tube axis of the sealed container. With this construction, the focusing electrode is fixed to the pair of insulating support members in a state that the focusing electrode is aligned with high accuracy by using the pair of insulating support member as a reference member.

Abstract: The present invention relates to a photomultiplier having a configuration for improving response time characteristics. The photomultiplier comprises a sealed container, a photocathode, and an electron multiplier section. The electron multiplier section has an upper unit and a lower unit. The upper unit includes a focusing electrode, a mesh electrode, and a first dynode. The lower unit includes the subsequent dynodes excluding the first dynode and a pair of insulating supporting members. The second dynode, belonging to the subsequent dynodes, is provided with a notch for partitioning effective regions for two adjacent electron multiplier channels. By this configuration, a sufficient discharge withstand voltage can be secured without having to modify electron trajectories.

Abstract: The present invention relates to a photomultiplier having a configuration for improving response time characteristics. The photomultiplier comprises at least a sealed container, a photocathode, and an electron multiplier section. The electron multiplier section has an upper unit and a lower unit. The upper unit includes a focusing electrode, a mesh electrode, and a first dynode. The lower unit includes the subsequent dynodes excluding the first dynode and a pair of insulating supporting members. The upper unit further includes partitioning plates for partitioning effective regions for plural electron multiplier channels that are assigned along the longitudinal direction of said first dynode in order to prevent crosstalk among the adjacent electron multiplier channels.

Abstract: The present invention relates to a photomultiplier having a configuration for improving response time characteristics. The photomultiplier comprises at least a sealed container, a photocathode, and an electron multiplier section. The electron multiplier section has an upper unit and a lower unit. The upper unit includes a focusing electrode, a mesh electrode, and a first dynode. The lower unit includes the subsequent dynodes excluding the first dynode and a pair of insulating supporting members. The length in the longitudinal direction of the first dynode is made greater than the interval between the pair of insulating supporting members. By this configuration, the sizes of the effective regions of the assigned electron multiplier channels can be set arbitrarily without being restricted by the pair of insulating supporting members.

Abstract: The present invention relates to a photomultiplier having a configuration for improving response time characteristics. The photomultiplier comprises at least a sealed container, a photocathode, and an electron multiplier section. The electron multiplier section has an upper unit and a lower unit. The upper unit includes a focusing electrode, a mesh electrode, and a first dynode, among a multiple stages of dynodes, being a dynode at which the photoelectrons from the photocathode arrive. The lower unit includes the subsequent dynodes while excluding the first dynode from the multiple stages of dynodes, and a pair of insulating supporting members that clampingly hold the subsequent dynodes. The mesh electrode is positioned in an inclined state with respect to a tube axis.

Abstract: The present invention relates to a photomultiplier that can realize a gain adjustment for each of electron multiplier channels respectively assigned to a plurality of light incidence regions in a more compact structure. The photomultiplier has a sealed container, and a photocathode, a dynode unit, and plurality of anodes prepared for electron multiplier channels are housed in the sealed container. The dynode unit is constituted by N (an integer or no less than 3) dynode plates, each provided with an electron multiplier hole for the associated channel, concerning all channels. In particular, the n-th (an integer of no less then 2) dynode plate is constituted by a plurality of control plates, each having an electron multiplier hole for the associated channel, and electrically and physically separated from the others. These control plates are supported in state of being supported, via insulators, by the (n?1)-th dynode plate and the (n+1)-th dynode plate.

Abstract: An amplifier circuit having an amplifier chain comprising an input port and output port with a plurality of interconnected gain stages positioned in between. The output of one interconnected gain stage provides an input to the next stage within the amplifier chain. The output port coupled to the plurality of interconnected gain stages such that the amplifier circuit output is generated from any one or more of the interconnected gain stages.

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: A glass container has a faceplate, a side tube, and a bottom. A photocathode is formed on the inner side of the faceplate. The glass container includes a first dynode, a second dynode, a screen focusing electrode, a dynode array, and an anode. The screen focusing electrode consists of a first screen, a second screen, a flat plate, and an aperture. The first screen is provided on the first dynode side of the aperture and extends across the lower end of the first dynode towards the photocathode. The second screen is provided on the second dynode side of the aperture and extends across the lower end of the second dynode towards the photocathode. A Venetian blind type is provided as the dynode array. The first dynode, the second dynode, the dynode array, and the anode are maintained at the potential which is higher than that of the photocathode. Electrons emitted from the photocathode in response to incident light thereon efficiently impinge on the dynodes regardless of where the electrons are emitted.

Abstract: A dynode constituting an electron multiplier or a photomultiplier may be provided with eight rows of channels each defined by an outer frame and a partitioning part of the dynode. In each channel, a plurality of electron multiplying holes may be arranged. In specified positions of the outer frame and the partitioning part of the dynode, glass receiving parts wider than the outer frame and the partitioning part may be provided integrally with the dynode. Glass parts may be bonded to all the glass receiving parts. The glass parts may be bonded by applying glass to the glass receiving parts and hardening the glass and each may have a generally dome-like convex shape. Each dynode may be formed after the dome-like glass part may be bonded to the glass receiving part.

Abstract: An inner surface of an electron-multiplier hole (14) includes a first curved surface (19a) and a second curved surface (19b) that face each other. The first curved surface (19a) extends from an edge of an input opening (14a) in such a way as to face the input opening (14a), and is shaped like a substantially circular arc having a predetermined radius. The second curved surface (19b) extends from an edge of an output opening (14b) in such a way as to face the output opening (14b), and is shaped like a substantially circular arc having a predetermined radius.

Abstract: A dynode (8) constituting an electron multiplier or a photomultiplier is provided with eight rows of channels (15) each defined by an outer frame (16) and a partitioning part (17) of the dynode (8). In each channel (15), a plurality of electron multiplying holes (14) are arranged. In specified positions of the outer frame (16) and the partitioning part (17) of the dynode (8), glass receiving parts (21) wider than the outer frame (16) and the partitioning part (17) are provided integrally with the dynode (8). Glass parts (22) are bonded to all the glass receiving parts (21). The glass parts (22) are bonded by applying glass to the glass receiving parts (21) and hardening the glass and each have a generally dome-like convex shape. Each dynode (8) is formed after the dome-like glass part (22) is bonded to the glass receiving part (21).

Abstract: A photomultiplier has a dynode cascade arranged radially rather than axially. Effective dynode area thereby can increase through the cascade, leading to improved linearity of response, and the axial length of the device can be reduced. The dynodes are sections of a set of toroids and may be formed as a layer of secondary emissive material such as caesiated antimony on a monolithic sintered cast or otherwise moulded or machined block of insulating material. This novel form of dynode construction can also be used in other photomultiplier or electron multiplier configurations.

Abstract: A photomultiplier that prevents rattling between the dynodes and the base plates, the parts being fixed securely to achieve excellent vibration resistance. The dynode of the second stage (Dy2) includes a curved surface (Dy2A) having an arcuate cross-section and a flat surface (Dy2B) formed continuously and flush with the curved surface. The curved surface (Dy2A) and flat surface (Dy2B) make up the secondary electron emitting surface. Side walls (Dy2C) erected from the curved surface (Dy2A) are formed through a pressing process on either lengthwise end of the curved surface (Dy2A). First ear portions (Dy2D) extend outward from both side walls (Dy2C). Second ear portions (Dy2E) extend outward from both lengthwise ends of the flat surface (Dy2B). The first and second ear portions (Dy2D and Dy2E) are not parallel to each other but form a fixed angle.

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: An improved electron multiplier bias network that limits the response of the multiplier when the multiplier is faced with very large input signals, but then permits the multiplier to recover quickly following the large input signal.

Abstract: A dynode (8) constituting an electron multiplier or a photomultiplier is provided with eight rows of channels (15) each defined by an outer frame (16) and a partitioning part (17) of the dynode (8). In each channel (15), a plurality of electron multiplying holes (14) are arranged. In specified positions of the outer frame (16) and the partitioning part (17) of the dynode (8), glass receiving parts (21) wider than the outer frame (16) and the partitioning part (17) are provided integrally with the dynode (8). Glass parts (22) are bonded to all the glass receiving parts (21). The glass parts (22) are bonded by applying glass to the glass receiving parts (21) and hardening the glass and each have a generally dome-like convex shape. Each dynode (8) is formed after the dome-like glass part (22) is bonded to the glass receiving part (21).

Abstract: An improved electron multiplier bias network that limits the response of the multiplier when the multiplier is faced with very large input signals, but then permits the multiplier to recover quickly following the large input signal.

Abstract: A photomultiplier eliminates the reflection of light off of focusing pieces in a focusing electrode and prevents the photocathode from emitting useless electrons in response to such reflected light by including an oxide film formed over the surface of each focusing piece. The oxide film is also formed on the surface of secondary electron emission pieces in the first and second stage dynodes to eliminate the reflection of light off of the secondary electron emission pieces and to prevent the photocathode from emitting useless electrons in response to such reflected light. Further, a light-absorbing glass partitioning part is provided in a light-receiving faceplate to suppress crosstalk between channels.

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: 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: A multi dynode device (MDD) for electron multiplication and detection and a hybrid detector using the MDD have high peak signal output currents and large dynamic range while preserving the time-dependent information of the input event and avoiding the generation of significant distortions or artifacts on the output signal. The MDD and hybrid detector overcome saturation problems observed in conventional hybrid detectors by providing a unique electron multiplier portion that avoids the path-length differences. The MDD and hybrid detector can be used in mass spectrometry, in particular, time-of-flight mass spectrometry. The MDD comprises a plurality of dynode plates arranged in a stacked configuration. Each dynode plate in the stack has a plurality of apertures for cascading secondary electrons through the stack. Each aperture comprises a mechanical bias or offset with respect to the apertures in adjacent plates. The offset is such that the electrons will impact with one or more of the dynode plates.

Abstract: An inner surface of an electron-multiplier hole (14) includes a first curved surface (19a) and a second curved surface (19b) that face each other. The first curved surface (19a) extends from an edge of an input opening (14a) in such a way as to face the input opening (14a), and is shaped like a substantially circular arc having a predetermined radius. The second curved surface (19b) extends from an edge of an output opening (14b) in such a way as to face the output opening (14b), and is shaped like a substantially circular arc having a predetermined radius.

Abstract: A photomultiplier that prevents rattling between the dynodes and the base plates, the parts being fixed securely to achieve excellent vibration resistance. The dynode of the second stage (Dy2) includes a curved surface (Dy2A) having an arcuate cross-section and a flat surface (Dy2B) formed continuously and flush with the curved surface. The curved surface (Dy2A) and flat surface (Dy2B) make up the secondary electron emitting surface. Side walls (Dy2C) erected from the curved surface (Dy2A) are formed through a pressing process on either lengthwise end of the curved surface (Dy2A). First ear portions (Dy2D) extend outward from both side walls (Dy2C). Second ear portions (Dy2E) extend outward from both lengthwise ends of the flat surface (Dy2B). The first and second ear portions (Dy2D and Dy2E) are not parallel to each other but form a fixed angle.

Abstract: A dynode (8) constituting an electron multiplier or a photomultiplier is provided with eight rows of channels (15) each defined by an outer frame (16) and a partitioning part (17) of the dynode (8). In each channel (15), a plurality of electron multiplying holes (14) are arranged. In specified positions of the outer frame (16) and the partitioning part (17) of the dynode (8), glass receiving parts (21) wider than the outer frame (16) and the partitioning part (17) are provided integrally with the dynode (8). Glass parts (22) are bonded to all the glass receiving parts (21). The glass parts (22) are bonded by applying glass to the glass receiving parts (21) and hardening the glass and each have a generally dome-like convex shape. Each dynode (8) is formed after the dome-like glass part (22) is bonded to the glass receiving part (21).

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: 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 has a dynode cascade arranged radially rather than axially. Effective dynode area thereby can increase through the cascade, leading to improved linearity of response, and the axial length of the device can be reduced. The dynodes are sections of a set of toroids and may be formed as a layer of secondary emissive material such as caesiated antimony on a monolithic sintered cast or otherwise moulded or machined block of insulating material. This novel form of dynode construction can also be used in other photomultiplier or electron multiplier configurations.

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: This invention relates to a photomultiplier tube including: a photocathode PK with a semi-transparent photo-sensitive layer provided to emit an electron flux towards the inside of the tube, focusing optics comprising a first dynode D1, concave on the side of the photocathode PK, and several Rajkman dynodes D3, . . . , D8 located on each side of a plane called the dynodes plane DP. According to the invention, the focusing optics also includes a second dynode D2 concave on the side of the re-emitting surface of the first dynode D1, the angle between the plane of the dynodes DP and the center line of the tube exceeding 45°, the concave side of the first Rajkman dynode D3 facing the re-emitting surface of the second dynode D2.

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 electron multiplier assembly 27, a dynode unit 10 is constructed from a plurality of dynodes 9 laminated one on another. Each dynode 9 is formed with multichannels 12 which are separated from one another by channel-separating portions 14. A focusing electrode plate 16 is formed with multichannels 18 which are separated from one another by channel-separating electrodes 20 which are located in correspondence with the channel-separating portions 14 of the first stage dynode 9a. A plurality of anodes 7 are provided for receiving electrons multiplied at the dynode unit 10 in their corresponding channels 18. Each channel-separating electrode 20 is formed with an opening 21, at a position confronting the channel-separating portion 14 of the first stage dynode 9a, for transmitting electrons therethrough.

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 tube is disclosed having a first dynode array and a second dynode array oriented substantially orthogonal to the first dynode to provide a shortened profile. The first dynode array is preferably a box-and-grid dynode array and the second dynode array is preferably an in-line dynode array. A focusing electrode is positioned between the last dynode of the first dynode array and the first dynode of the second dynode array. The focusing electrode is constructed and arranged to facilitate the transfer of electrons emitted from the first dynode array to the second dynode array without generating secondary electrons.

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: 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: A photomultiplier includes a photocathode (3); an electron multiplier section (60) for cascade-multiplying photoelectrons emitted from the photocathode (3); a faceplate (2) provided with the photocathode (3); a metal housing (1) accommodating the photocathode (3) and the electron multiplier section (60); and a structure disposed on the faceplate (2) for increasing the effective light entrance region of the faceplate (2). In a preferred embodiment the subject structure includes a lens element (30) attached to the faceplate for increasing the effective light entrance region of the faceplate (2). In order to improve the optical coupling efficiency, either the faceplate (2), or the lens element (30), or both the faceplate (2) and the lens element (30) may further include a protrusion.

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.