Abstract:
A detector unit for detecting photons in the energy range 1 keV to 100 MeV, includes at least two converter layers adapted to interact with incident X-ray photons and to cause electrons to be emitted therefrom, at least one amplifier adapted to interact with the electrons emitted from the converters and adapted to produce a multiplicity of secondary electrons and photons representing a signal proportional to the incident fluence of X-ray photons, a connector connecting the detector to an electric field generator providing an electric drift field for secondary electrons in the detector, and a sensor device arranged to receive the signal and provide an input to electronic signal processor.
Abstract:
A multi dynode device (MDD) for electron multiplication and detection and a hybrid detector using the MDD have high peak signal output currents and large dynamic range while preserving the time-dependent information of the input event and avoiding the generation of significant distortions or artifacts on the output signal. The MDD and hybrid detector overcome saturation problems observed in conventional hybrid detectors by providing a unique electron multiplier portion that avoids the path-length differences. The MDD and hybrid detector can be used in mass spectrometry, in particular, time-of-flight mass spectrometry. The MDD comprises a plurality of dynode plates arranged in a stacked configuration. Each dynode plate in the stack has a plurality of apertures for cascading secondary electrons through the stack. Each aperture comprises a mechanical bias or offset with respect to the apertures in adjacent plates. The offset is such that the electrons will impact with one or more of the dynode plates. The MDD further comprises a power source to provide a voltage bias to the dynode plates. The power source comprises a voltage supply and a voltage divider. Each dynode plate is connected to a tap on the voltage divider such that a voltage gradient is produced along the stack. The MDD can supply high peak currents. The hybrid detector comprises an input portion having a microchannel plate MCP and an output portion having the multi dynode device (MDD). The MCP and MDD are adjacent to one another. The MDD is planar, flat, and compact like that of the MCP, such that important temporal integrity of an input signal event is preserved.
Abstract:
A universal contact assembly for an image intensifier tube wherein the pin socket and flat are both parts of an integrally formed unit. The pin socket has a through hole for accepting a wire lead to be soldered. A method of making a universal contact assembly wherein the pin socket shell and flat are machined from a single piece.
Abstract:
The present invention comprises a photon detector and image generator, which includes a photocathode that receives photons from an image. The photocathode discharges electrons in response to the received photons. A microchannel plate with an unfilmed input face and an output face receives the electrons from the photocathode and produces secondary emission electrons which are emitted from the output face. A display receives the secondary electrons and displays a representation of the image. The photon detector and image generator has a lifetime of more than 7,500 hours.
Abstract:
There is disclosed a three draw technique for drawing optical fibers into various cross-sectional shapes. The process employs a glass tube and rod which are fed into a heated furnace. The viscosity of the glass decreases and the glass flows. The glass is pulled or drawn out of the furnace at a different rate than it is fed into the furnace. The resultant drawn fibers are stacked and the process is repeated two more times. By employing three drawing steps one can achieve extremely small fiber faces. The final draw step uses a hexagonal cross-section preform and fibers. From the first drawn fibers three geometrical shapes can be assembled and finally drawn into hexagonal shapes with round fibers which are triangles, rhombohedrials and half hex or trapezoidal shapes. These shapes maintain the hexagonal closely packed space providing the highest density per cross-section. With this high density there is less glass flowing to fill voids thereby reducing distortion within the fabricated MCP. The final reduction ratio of the starting material to the finished device is the product of each reduction ratio of the individual draw steps.
Abstract:
A replaceable, electronically-isolated, MCP-based spectrometer detector cartridge with enhanced sensitivity is disclosed. A coating on the MCP that enhances the secondary electron emissivity characteristics of the MCP is selected from aluminum oxide (Al2O3), magnesium oxide (MgO), tin oxide (SnO2), quartz (SiO2), barium fluoride (BaF2), rubidium tin (Rb3Sn), beryllium oxide (BeO), diamond and combinations thereof A mass detector is electro-optically isolated the from a charge collector with a method of detecting a particle including accelerating the particle with a voltage, converting the particle into a multiplicity of electrons and converting the multiplicity of electrons into a multiplicity of photons. The photons then are converted back into electrons which are summed into a charge pulse. A detector also is provided.
Abstract:
In a photomultiplier tube 1, an etching technique is used to form electron multiplying holes 8a in plate-shaped dynodes 8 that are stacked in multiple layers. To perform this etching process, a pattern frame 22 is disposed around a plate-shaped dynode substrate 20. A bridge portion 23 is provided for connecting the pattern frame 22 to an edges 20a of the dynode substrate 20. The dynode substrate 20 is masked, and the etching process is performed to form a plurality of electron multiplying holes 8a in the dynode substrate 20. Subsequently, the bridge portion 23 is cut near the dynode substrate 20, leaving a small bridge remainder 8c on the edge 8b of the dynode 8. In order to suppress noise generated by these bridge remainders, the bridge remainders 8c on neighboring dynodes 8 are arranged in positions such that straight lines parallel to the dynode stacking direction and passing through the bridge remainder 8c do not overlap each other, thereby further improving the basic characteristics of the photomultiplier tube 1.
Abstract:
A particle and photon detector includes a body having a beam-incident surface (8) capable of releasing secondary electrons in numbers proportional to the number of particles incident on the surface, and a plurality of secondary electron multiplier channels (4) whose inlet openings are disposed in the beam-incident surface, therewith to amplify the number of secondary electrons. A center channel (2) extends from the beam-incident surface (8) through the detector body and enables a beam of particles or photons to pass through the body. The inlet openings of the secondary electron multipliers are conveniently disposed in the beam-incident surface in a ring around the center channel for receiving secondary electrons. The method applied in the detection of charged particles, such as ions and electrons, in a beam that contains charged and charge-free particles comprises the steps of subjecting the charged particles to the effect of an electric field so as to collect the charged particles in an outer tubular layer or beam which surrounds the residual beam of charge-free particles, such as to form two mutually, coaxial beams, wherein the outer tubular particle beam is captured by a plurality of secondary electron multipliers and wherein signals delivered by the electron multipliers are read-off.
Abstract:
Microchannel plates are provided having an array of multiple channel electron multipliers for use in night vision devices, image intensifier tubes, photomultiplier tubes, and other such devices with improved gain, higher signal-to-noise ratio, and better resolution. The microchannel plates disclosed herein utilize a bulk-conductivity substrate material, and provide features for improving secondary electron-emissivity of the material.
Abstract:
An image intensifier and electron multiplier therefor is disclosed. Photons of an image impinge a photo-cathode that converts the photons to electrons. An electron multiplier multiplies the electrons from the photo-cathode to create an increased number of electrons. A sensor captures the increased number of electrons to produce an intensified image. The electron multiplier is an electron bombarded device (EBD) containing a semiconductor structure. The semiconductor structure has an input surface for receiving electrons and an emission surface for passing an increased number of electrons. The semiconductor structure is doped to direct the flow of electrons through the semiconductor structure to an emission area on the emission surface.