摘要:
A photomultiplier comprising an electron multiplier for minimizing a variation in multiplication factor and noise is characterized in that insulating members are aligned on the same line to insulate a plurality of dynode plates for constituting a dynode unit from each other, thereby preventing a damage to each dynode plate. At the same time, a through hole is formed to fix the insulating member provided to each dynode plate such that a gap is provided between the major surface of the dynode plate and the surface of the insulating member, thereby preventing discharge between dynode plates, which is caused due to dust or the like deposited on the surface of the insulating member.
摘要:
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.
摘要:
A photomultiplier which can be easily made compact has a dynode unit constituted by stacking a plurality of stages of dynode plates in an electron incident direction in a vacuum container constituted by a housing and a base member integrally formed with the housing. Each dynode plate has an engaging member engaged with a connecting pin for applying a voltage at a side surface thereof. Through holes for guiding the connecting pins from the outside of the container are formed in the base member. Each engaging member is arranged not to overlap the remaining engaging members in the stacking direction of the dynode plates. The arrangement position of each engaging member and the arrangement position of the through hole for guiding the corresponding connecting pin to be connected are matched with each other.
摘要:
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.
摘要:
A photomultiplier includes a photocathode and an electron multiplier. A typical structure of the electron multiplier is obtained such that a dynode unit constituted by stacking a plurality of dynode plates in the incident direction of photoelectrons, an anode plate, and an inverting dynode plate are stacked. The anode plate has electron through holes at a predetermined portion to cause secondary electrons emitted from the dynode unit to pass therethrough. Each electron through hole has a diameter on the inverting dynode plate side larger than that on the dynode unit side, thereby increasing the capture area of the secondary electrons orbit-inverted by the inverting dynode plate.
摘要:
A photomultiplier has a focusing electrode plate for supporting focusing electrodes, provided between a photocathode and a dynode unit. Since the focusing electrode plate has holding springs which are integrally formed with the focusing electrode plate, resistance-welding becomes unnecessary to prevent field discharge. A concave portion is formed in a main surface of the focusing electrode plate to arrange an insulating member sandwiched between the focusing electrode plate and the photoelectron incidence side of the dynode unit and partially in contact with the concave portion. With this structure, discharge between the focusing electrode plate and the dynode unit can be prevented.
摘要:
A photomultiplier which can be easily made compact has a dynode unit having a plurality of dynode plates stacked in an electron incident direction in a vacuum container fabricated by a housing and a base member integrally formed with the housing. Each dynode plate is constituted by welding at least two plates overlapping each other. The welding positions do not overlap each other in the stacking direction of the dynode plates. With this structure, field discharge at the welding portions between the dynode plates can be prevented to reduce noise.
摘要:
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.
摘要:
A vacuum vessel is configured by hermetically joining a faceplate to one end of a side tube and a stem to the other end via a tubular member. A photocathode, a focusing electrode, dynodes, a drawing electrode, and anodes are arranged within the vacuum vessel. The dynodes and the anodes have a plurality of channels in association with each other. Each electrode has cutout portions that overlap in a stacking direction, and supporting pins and lead pins are arranged in the cutout portions. A bridge is provided in a concave section arranged between unit anodes, and the bridge is cut off after the anode plate is placed on stem pins. Effective areas of each electrode and the anode are secured sufficiently, thereby allowing electrons to be detected efficiently.
摘要:
A vacuum vessel is configured by hermetically joining a faceplate to one end of a side tube and a stem to the other end via a tubular member. A photocathode, a focusing electrode, dynodes, a drawing electrode, and anodes are arranged within the vacuum vessel. The dynodes and the anodes have a plurality of channels in association with each other. Each electrode has cutout portions that overlap in a stacking direction, and supporting pins and lead pins are arranged in the cutout portions. A bridge is provided in a concave section arranged between unit anodes, and the bridge is cut off after the anode plate is placed on stem pins. Effective areas of each electrode and the anode are secured sufficiently, thereby allowing electrons to be detected efficiently.