Abstract:
An MCP has a rectangular plate shape and has a porous part, to which a plurality of pores (channels) penetrating in the thickness direction are disposed, and a poreless part including a solid glass or the like to which the channels are not provided on the both sides of the porous part. Then, on both surfaces of the MCP, an input side electrode and an output side electrode are respectively formed so as to cover the poreless parts on the both surfaces while sandwiching the porous part.
Abstract:
Back-illuminated silicon photomultipliers having a substrate of a first conductivity type having front and back sides, a matrix of regions of a second conductivity type in the substrate, a matrix of regions of the first conductivity type under the matrix of regions of the second conductivity type and adjacent the back side of the substrate, with the bottom of the matrix of regions of the second conductivity type forming a p/n junction with the substrate or a matrix of regions of the second conductivity type, the matrix of regions of the first conductivity type having a higher conductivity than the substrate, a common anode formed by a uniform layer of the first conductivity type of higher conductivity than the substrate on the back side of the substrate. Preferably a plurality of trenches filed with an opaque material are provided in the back side of the substrate, the substrate preferably having a thickness of less than approximately 150 um.
Abstract:
A time-resolved measurement apparatus (100) reads a detection timing pulse from an MCP (24) in a front-side MCP stack (30) in a photomultiplier tube (14). A detection timing of a photon is determined based on this pulse. A principal component of this pulse is a potential rise pulse in response to the emission of photoelectrons from the MCP (24), and it has the positive polarity. On the other hand, when photoelectrons are incident on the front-side stack (30), a pulse of the negative polarity is generated to deform the waveform of the detection timing pulse. However, since the number of the photoelectrons incident on the front-side stack (30) is fewer than that of those incident on a rear-side stack (32), the negative component is small in the detection timing pulse. This results in enhancing the time precision of the time-resolved measurement.
Abstract:
An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.
Abstract:
A vacuum vessel is configured by hermetically joining a faceplate (13) to one end of a side tube (15) and a stem (29) to the other end via a tubular member (31). A photocathode (14), a focusing electrode (17), dynodes (Dy1-Dy12), a drawing electrode (19), and anodes (25) are arranged within the vacuum vessel. At the center of the stem (29) an air discharging tube (40) is connected. The air discharging tube (40) includes an outer side tube (41) and an inner side tube (43), which are disposed coaxially and connected to each other at the stem (29) side. The outer side tube (41) has high adhesiveness with the stem (29) and the inner side tube (43) is thin and has small stress when being cut, thereby enabling the joint with the vacuum vessel not to be damaged when the air discharging tube (40) is sealed.
Abstract:
The present invention relates to a photomultiplier having a configuration for improving response time characteristics. The photomultiplier comprises at least a sealed container, a photocathode, and an electron multiplier section. The electron multiplier section has an upper unit and a lower unit. The upper unit includes a focusing electrode, a mesh electrode, and a first dynode. The lower unit includes the subsequent dynodes excluding the first dynode and a pair of insulating supporting members. The length in the longitudinal direction of the first dynode is made greater than the interval between the pair of insulating supporting members. By this configuration, the sizes of the effective regions of the assigned electron multiplier channels can be set arbitrarily without being restricted by the pair of insulating supporting members.
Abstract:
The edges of portions of a base member that are joined to stem pins are arranged as bottom surfaces of recesses formed in the stem so that the stem pins are joined to the base member at gradual angles and so that even when a bending force acts on the stem pins, the stem pins will contact the peripheral portions at the open sides of the recesses, thereby preventing further bending of the stem pins and preventing the forming of cracks at both sides of the portions at which the stem pins are joined to the base member. Furthermore, triple junctions, at which the conductive stem pins, the insulating base member to which the stem pins are joined, and vacuum intersect, are positioned inside the recesses and put in concealed-like states.
Abstract:
A solid state photodetector is disclosed comprising a multiplicity of photodetector elements, each element using clamped Geiger mode gain to achieve high sensitivity and high speed. The elements are connected together using a common anode to sum their outputs, allowing operation with gray-scale response over a large total photosensitive area. In the preferred embodiment, high speed performance is achieved by isolating each element from the bias supply by means of an integrated series resistor.
Abstract:
An integrated micro-photomultiplier is disclosed which employs sub-micron-wide channels for electron amplification. These channels are created with standard lithographic and planar-fabrication techniques, and sealed with a vacuum-deposition process. A photocathode, continuous dynode, anode and signal-collector are fabricated along the channels. This photomultiplier design obviates the needs for through-substrate etching, and mechanical assembly of separate layers. Because large-scale-integration techniques can be used to fabricate multiple micro-photomultipliers, significant reductions in device cost and size are expected. The integrated micro-photomultiplier is useful for high-speed, low-light-level optical detection, and may find applications in optical communications, visible or infrared imaging, and chemical or biological sensing.
Abstract:
A photomultiplier tube enhanced in simplicity and flexibility of mounting, a photomultiplier tube unit enhanced in photomultiplier tube assembling efficiency when unitized, and a radiation detector enhanced in assembling efficiency for a plurality of photomultiplier tubes. The photomultiplier tube (1) has a hermetically sealed vessel (5) easily screw-fixed in a predetermined position due to screwing means (30) provided in the stem plate (4). As a result, the photomultiplier tube (1) can be very easily attached or detached so that even an unskilled person can mount the photomultiplier tube (1) easily and accurately in a predetermined position by screwing.