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

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

Abstract: A 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An electron lens electrode for guiding photoelectrons emitted from a photocathode to an electron multiplier section is arranged between the photocathode and the light-incident portion of a sealed container, and an opening is formed at a portion of the electron lens electrode opposing the light-incident portion. Incident light reaches the photocathode through the opening without being scattered or absorbed at all. The transmittance of light incident on a photomultiplier is improved, and the output waveform is uniformed, resulting in an improved S/N ratio.

Abstract: This invention relates to a semiconductor photo-electron-emitting device for emitting photoelectrons excited from the valence band to the conduction band by incident photons on a semiconductor layer. The device includes a Schottky electrode formed on the emitting surface on a surface of the semiconductor layer, and a conductor layer formed on a surface opposite to the emitting surface. A set bias voltage is applied between the Schottky electrode and the conductor layer to accelerate photoelectrons generated by the excitation of incident photons to the emitting surface and to transfer the accelerated photoelectrons from an energy band of a smaller effective mass to an energy band of a larger effective mass.