摘要:
A photocathode is formed on a predetermined portion of the internal surface of an envelope of an electric tube. An avalanche photodiode (APD) is provided inside the envelope. The APD is surrounded by a cover and a tubular inner wall. A manganese bead and an antimony bead serving as evaporation sources are disposed in the vicinity outside the inner wall. The manganese bead and the antimony bead are surrounded by a tubular outer wall. The manganese bead and the antimony bead generate metal vapor to thereby form the photocathode. In forming the photocathode, the cover, inner wall, outer wall prevent the metal vapor from being deposited on the APD or an unintended portion inside the electron tube.
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:
In an electron tube, one end of an insulating tube is protruded toward the inside of an envelope, and an avalanche photodiode (APD) is provided on the one end of the insulating tube. Another end of the insulating tube is connected to an outer stem of the envelope. Alkali sources are provided inside the envelope. The alkali sources are disposed inside the envelope and generates alkali metal vapor to thereby form a photocathode on a predetermined part of the internal surface of the envelope. The alkali sources and insulating tube are isolated from each other by a separating member. When the electron tube is manufactured, the alkali metal vapor that is generated from the alkali sources is not deposited on the insulating tube due to existence of the separating member. This prevents voltage resistance between the envelope and APD from being decreased and the electrical field in the electron tube from being adversely affected, thereby preventing incident efficiency of electrons to the APD from being decreased.
摘要:
In an electron tube, an insulating tube protrudes inside an envelope. One end of the insulating tube is connected to the envelope. An avalanche photo diode (APD) is provided on the other end of the insulating tube. A ground voltage is applied to the envelope and a positive high voltage is applied to the APD. Photoelectrons which are emitted in response to an incident light on a photocathode are converged by an electrical field in the envelope and enter the APD. Thereafter, the incident photoelectrons are amplified and detected. Since a positive high voltage is not exposed to the envelope, the electron tube can easily be handled and is excellent in safety.
摘要:
An insulating tube has one end and another end. An An avalanche photodiode (APD) is provided outside the one end of the insulating tube. The another end of the insulating tube is air-tightly connected to an outer flange through a stem inner wall. Capacitors electrically connected to the APD are provided in the insulating tube. The capacitors remove direct current components from signals that the APD generates when detecting electrons. By providing the capacitors in the insulating tube, response of output signals can be prevented from being impaired.
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 venetian-blind type of photomultiplier tube comprising a photocathode for converting an incident light into photoelectrons, a venetian-blind type of dynode array comprising plural dynode rows arranged in a first direction, each of which comprises plural dynode elements arranged at a constant pitch in a second direction, each dynode element having a plate inclined to the first direction for emitting the secondary electrons, an anode array comprising plural anodes arranged in the second direction for collecting the secondary electrons emitted from the dynode array and outputting an amplified electrical signal corresponding to the light, and one or more electron converging electrodes for converging at least one stream of the photoelectrons and the secondary electrons and concentrically directing the converged stream to a predetermined portion of each of the dynode elements. The electron-flight control member may have various patterns such as a grid, strip, mesh and multi-aperture structures.
摘要:
A photomultiplier tube comprising a photocathode, a plurality of mesh dynodes arranged parallel to the photocathode, an anode that is disposed in a face-to-face relationship with the photocathode in such a manner that the mesh dynodes are interposed between the anode and the photocathode, the anode being divided into segments larger than the openings of each dynode, and at least one layer of focusing electrode for focusing an electron beam by the lens action which is disposed between the photocathode and the anode.
摘要:
An electron multiplier device consists of an insulating substrate having, a plurality of through-holes, a first secondary electron emission layer and a second secondary electron emission layer or a conductive layer, and a DC electric field is applied to the first secondary electron emission layer with respect to the second latter secondary electron emission layer or conductive layer.