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 that realizes significant improvement of response time properties with a structure enabling mass production. The photomultiplier comprises a sealed container, and the sealed container includes a hollow body section, extending along a tube axis, and a faceplate. The faceplate has a light incidence surface and a light emission surface on which a photocathode is formed. In particular, the light emission surface is constituted by a flat region, and a curved-surface processed region that is positioned at a periphery of the flat region and that includes edges of the light emission surface. A surface shape of the peripheral region of the light emission surface of the faceplate is thus intentionally changed in order to adjust the angles of emission of photoelectrons from the photocathode positioned at the peripheral region.

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: The present invention relates to a photomultiplier of a fine structure that realizes a high multiplier efficiency. The photomultiplier comprises an outer casing whose interior is maintained at vacuum, and, in the outer case, a photocathode that emits photoelectrons in response to incident light, an electron multiplier section that performs cascade multiplication of the photoelectrons emitted from the photocathode, and an anode for taking out secondary electrons, which are generated at the electron multiplier section, are arranged. In particular, groove portions for performing cascade multiplication of electrons from the photocathode are provided in the electron multiplier section, and on the respective surfaces of each pair of wall portions that define the groove portions are provided with one or more protrusions each having a secondary electron emitting surface formed on the surface thereof.

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: 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 partitioning wall, a shield electrode, a first dynode, a second dynode, a dynode array, and an anode. The partitioning wall has a cross shape to divide an electron focusing space into four space segments. The shield electrode is provided to shield the second dynode from the photocathode. A Venetian blind type of dynodes 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. The electrons are multiplied and then detected by the anode.

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: This invention relates to an electron multiplier unit and others enabling cascade multiplication of electrons through successive emission of secondary electrons in multiple stages in response to incidence of primary electrons. The electron multiplier unit has a first support member provided with an inlet aperture for letting primary electrons in, and a second support member located so as to face the first support member. The first support member is provided with a focusing electrode functioning to alter trajectories of the primary electrons, in order to guide the primary electrons to the inlet aperture. These first and second support members hold an electron multiplication section for the cascade multiplication and an anode.

Abstract: This invention relates to an electron multiplier unit and others enabling cascade multiplication of electrons through successive emission of secondary electrons in multiple stages in response to incidence of primary electrons. The electron multiplier unit has a first support member provided with an inlet aperture for letting primary electrons in, and a second support member located so as to face the first support member. These first and second support members hold an electron multiplication section for the cascade multiplication and an anode. The electron multiplication section is comprised of at least a first dynode of a box type and a second dynode having a reflection type secondary electron emission surface located so as to face the first dynode and arranged to receive secondary electrons from the first dynode and to emit secondary electrons to a side where the first dynode is located.

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 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 photomultiplier excellent in vibration resistance and improved in pulse linearity characteristic and time-response. The fourth, and sixth to ninth dynodes (Dy4, Dy6 to Dy9) have a similar shape to that of the second dynode (Dy2). The third and fifth dynodes (dy3, Dy5) are smaller than the dynode (Dy2). The first to tenth dynodes (Dy1 to Dy10) are so arranged that the dynode inner space path defined between opposed dynodes is perpendicular to the tube axis (X). The anode (A) is a mesh anode (A), and is opposed to the dynode (Dy2) with respect to the tube axis (X).

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: 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 photomultiplier excellent in vibration resistance and improved in pulse linearity characteristic and time-response. The fourth, and sixth to ninth dynodes (Dy4, Dy6 to Dy9) have a similar shape to that of the second dynode (Dy2). The third and fifth dynodes (dy3, Dy5) are smaller than the dynode (Dy2). The first to tenth dynodes (Dy1 to Dy10) are so arranged that the dynode inner space path defined between opposed dynodes is perpendicular to the tube axis (X). The anode (A) is a mesh anode (A), and is opposed to the dynode (Dy2) with respect to the tube axis (X).

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 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 hood electrode attached to a tip portion of a target is provided with an electron passage port widening on the side opposite from an x-ray emitting window, so that electrons emitted from an electron gun are made incident on the front end face of a target at a position on the x-ray emission side, whereby the distance between the x-ray generating position and the x-ray emitting window can be shortened.

Abstract: In an image intensifier comprising an entrance faceplate, made of a material transparent to light, having a photoelectric surface, formed on a surface opposite to a light entrance surface, for photoelectrically converting incident light into an electron; and an optical fiber block, constituted by a plurality of optical fibers bundled together, having a phosphor face at an end face of each optical fiber on the light entrance side, for emitting light in response to the electron incident thereon; the photoelectric surface of the entrance faceplate and the phosphor face of the optical fiber block opposing each other, while a vacuum atmosphere being formed therebetween; the optical fiber block is provided with a pit in which an end face of a core portion of each optical fiber is recessed from an end face of a cladding portion thereof, the bottom of the pit is filled with a phosphor, the surface of this phosphor is provided with a metal back layer, the cladding portion projects from the surface of the phosphor towa