Abstract:
Photomultiplier tube (10) comprising a photocathode (20), a first cylindrical dynode (30), an electron multiplier device (40) of the "leaf" type, and a device (50) for coupling the first dynode (30) to the multiplier device (40). According to the invention, the said coupling device (50) consists, on the one hand, of a first electrode (51) composed of a cylindrical lateral plate (52) of axis parallel to that of the multiplier device and of an upper plate (53) pierced by an opening (54) for passage of the photoelectrons (21) towards the first dynode (30), and, on the other hand, of a second plane electrode (55) situated between the exit (32) of the first dynode (30) and the entrance (42) of the multiplier device (40).
Abstract:
Photomultiplier tube 10 segmented into a plurality of elementary photomultipliers 11 comprising a photocathode 12 and a multiplier 13 of the type using sheets partitioned into a plurality of elementary multipliers 14. According to the invention the input space of the tube 10 located between the photocathode 12 and the multiplier 13 is partitioned into elementary input spaces 15 associated with the elementary photomultipliers and defining a plurality of elementary photocathodes 16, with each elementary input space 15 having a focussing electrode which causes the photo-electrons emitted by the associated elementary photocathode 16 to converge on the corresponding elementary multiplier 14.
Abstract:
An electron tube having an evacuated envelope includes therein an insulating substrate with a photoemissive cathode thereon. The cathode comprises a plurality of discrete substantially isolated photoemissive regions. A plurality of spaced apart conductive strips are disposed on the substrate and interconnect each of the photoemissive regions.
Abstract:
An electron discharge tube comprises an evacuated envelope, a photocathode within the envelope and a primary dynode having an active portion substantially coplanar with the photocathode. The active portion of the dynode has an oxide secondary emitting surface. A substantially uniform layer of an alkali antimonide compound is formed on substantially all of the oxide secondary emissive surface of the dynode.
Abstract:
In a photoelectric conversion device, the potential control unit controls electric potentials applied to the meta-surface. The meta-surface includes a plurality of patterns which are space away from each other. The plurality of patterns include an antenna portion and at least one bias portion. The antenna portion extends in a predetermined direction and emits the electron in response to incidence of the electromagnetic wave. The potential control unit switches a first state and a second state by controlling the electric potentials applied to the plurality of patterns. In the first state, a component of an electric field from the bias portion toward the antenna portion in a predetermined direction is positive. In the second state, a component of an electric field from the bias portion toward the antenna portion in the predetermined direction is negative.
Abstract:
In-situ methods for the batch fabrication of flat-panel micro-channel plate (MCP) photomultiplier tube (PMT) detectors (MCP-PMTs), without transporting either the window or the detector assembly inside a vacuum vessel are provided. The method allows for the synthesis of a reflection-mode photocathode on the entrance to the pores of a first MCP or the synthesis of a transmission-mode photocathode on the vacuum side of a photodetector entrance window.
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 accelerating electrode composes a lower electrode and an upper electrode fixed each other by welding at a plurality of spots. The lower electrode is held at a pair of insulating support members in a state for the pair of insulating support members to grasp unitedly it together with the dynode unit and anode. Additionally, the upper electrode has one or more slit grooves for pinching a part of the pair of insulating support members. With this construction, the accelerating electrode constituted by the lower electrode and upper electrode is fixed at the pair of insulating support members in a state to be aligned with high accuracy by using the pair of insulating support members as a reference member.
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. As a result, on assembly of the electron-multiplying unit, alignment work with high precision between the members, specific fixing members and fixing jigs becomes unnecessary, which enables to improve drastically the productivity of the electron-multiplying unit placed in the sealed container.
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 accelerating electrode composes a lower electrode and an upper electrode fixed each other by welding at a plurality of spots. The lower electrode is held at a pair of insulating support members in a state for the pair of insulating support members to grasp unitedly it together with the dynode unit and anode. Additionally, the upper electrode has one or more slit grooves for pinching a part of the pair of insulating support members. With this construction, the accelerating electrode constituted by the lower electrode and upper electrode is fixed at the pair of insulating support members in a state to be aligned with high accuracy by using the pair of insulating support members as a reference member.