Abstract: For each photomultiplier tube in an Anger camera, an R×S array of preamplifiers is provided to detect electrons generated within the photomultiplier tube. The outputs of the preamplifiers are digitized to measure the magnitude of the signals from each preamplifier. For each photomultiplier tube, a corresponding summation circuitry including R row summation circuits and S column summation circuits numerically add the magnitudes of the signals from preamplifiers for each row and for each column to generate histograms. For a P×Q array of photomultiplier tubes, P×Q summation circuitries generate P×Q row histograms including R entries and P×Q column histograms including S entries. The total set of histograms include P×Q×(R+S) entries, which can be analyzed by a position calculation circuit to determine the locations of events (detection of a neutron).

Abstract: For each photomultiplier tube in an Anger camera, an R×S array of preamplifiers is provided to detect electrons generated within the photomultiplier tube. The outputs of the preamplifiers are digitized to measure the magnitude of the signals from each preamplifier. For each photomultiplier tube, a corresponding summation circuitry including R row summation circuits and S column summation circuits numerically add the magnitudes of the signals from preamplifiers for each row and for each column to generate histograms. For a P×Q array of photomultiplier tubes, P×Q summation circuitries generate P×Q row histograms including R entries and P×Q column histograms including S entries. The total set of histograms include P×Q×(R+S) entries, which can be analyzed by a position calculation circuit to determine the locations of events (detection of a neutron).

Abstract: A neutron detector employs a porous material layer including pores between nanoparticles. The composition of the nanoparticles is selected to cause emission of electrons upon detection of a neutron. The nanoparticles have a maximum dimension that is in the range from 0.1 micron to 1 millimeter, and can be sintered with pores thereamongst. A passing radiation generates electrons at one or more nanoparticles, some of which are scattered into a pore and directed toward a direction opposite to the applied electrical field. These electrons travel through the pore and collide with additional nanoparticles, which generate more electrons. The electrons are amplified in a cascade reaction that occurs along the pores behind the initial detection point. An electron amplification device may be placed behind the porous material layer to further amplify the electrons exiting the porous material layer.

Abstract: A neutron detector employs a porous material layer including pores between nanoparticles. The composition of the nanoparticles is selected to cause emission of electrons upon detection of a neutron. The nanoparticles have a maximum dimension that is in the range from 0.1 micron to 1 millimeter, and can be sintered with pores thereamongst. A passing radiation generates electrons at one or more nanoparticles, some of which are scattered into a pore and directed toward a direction opposite to the applied electrical field. These electrons travel through the pore and collide with additional nanoparticles, which generate more electrons. The electrons are amplified in a cascade reaction that occurs along the pores behind the initial detection point. An electron amplification device may be placed behind the porous material layer to further amplify the electrons exiting the porous material layer.

Abstract: A detection system for wavelength-dispersive and energy-dispersive spectrometry comprises an X-ray detector formed from a solid-state avalanche photodiode with a thin entrance window electrode that permits the efficient detection of X-rays scattered from “light” elements. The detector can be tilted relative to the incident X-rays in order to increase the detection efficiency for X-rays scattered from “heavy” elements. The entrance window may be continuous conductive layer with a thickness in the range of 5 to 10 nanometers or may be a pattern of conductive lines with “windowless” areas between the lines. A signal processing circuit for the avalanche photodiode detector includes an ultra-low noise amplifier, a dual channel discriminator, a scaler and a digital counter. A linear array of avalanche photodiode detectors is used to increase the count rate of the detection system.

Abstract: An X-ray detector is formed with a geometry in the form of a spherical polygon, including an entrance window, a grid and an anode. The spherical polygonal entrance window and the grid form a spherical polygonal drift region between them. The electric field in this region is radial and eliminates parallax broadening. A spherical polygonal amplification region between a resistive anode on an insulating support and the grid allows very high gas amplification and good protection against spark discharges. A readout electrode on the back side of the anode insulator detects induced charges and protects the readout electronics against sparks.

Abstract: An X-ray detector includes one or more photodetectors embedded in scintillating material. The photodetectors may have a needle-like, a column-like, or a ridge-like structure. The scintillating material is applied over the photodetector which can either be a p?i?n type diode, an n?i?p type diode, a Schottky diode, or an avalanche diode.

Abstract: An electron multiplication apparatus uses a matrix of dielectric particles interspersed with conductive particles. Typically a porous layer of metal oxide and relatively inert metal, the material provides high electron count rates while maintaining good temperature stability. The layer is located between a cathode and an anode that together provide desired voltage differentials. A mesh is also used on a side of the matrix layer opposite the cathode to conduct surface charge away from the matrix, while providing an intermediate voltage potential between that of the anode and the cathode. A voltage source is used to generate the voltage potentials for each of the anode, cathode and mesh layer, and the resulting electric fields provide a device that may be used in the detection of high energy particles and photons, such as x-rays. A preferred method of fabricating the material involves the codeposition of a metal prone to oxidation and a relatively inert metal to form a porous layer.

Abstract: A detection apparatus for detecting an electron cloud includes a resistive anode layer with a detection plane upon which the electron cloud is incident. The resistive layer is capacitively coupled to a readout structure having a conductive grid parallel to the detection plane. Charge on the resistive layer induces a charge on the readout structure, and currents in the grid. The location of the induced charge on the readout structure corresponds to the location on the detection plane at which the electron cloud is incident. Typically, the detection apparatus is part of a detector, such as a gas avalanche detector, in which the electron cloud is formed by conversion of a high-energy photon or particle to electrons that undergo avalanche multiplication. The spacing between the anode layer and the readout structure is selected so that the width of the charge distribution matches the pitch between conductive segments of the grid.