A neutron imaging system includes a neutron generator, a flight tube, a stage, a neutron imaging module, and a neutron shield. The flight tube enables neutrons from the neutron generator to enter the flight tube through an input opening and exit through an output opening. The stage supports a sample object to receive neutrons that pass through the entire length of the flight tube and the output opening. The neutron imaging module has a neutron-sensitive component that receives neutrons that pass through the sample object and generates neutron detection signals. The neutron shield surrounds at least a portion of the flight tube and the neutron imaging module to block at least a portion of stray neutrons that travel toward the neutron-sensitive component of the neutron imaging module, in which the stray neutrons do not enter the flight tube through the input opening of the flight tube.
A neutron imaging system includes a neutron generator, a flight tube, a stage, a neutron imaging module, and a neutron shield. The flight tube enables neutrons from the neutron generator to enter the flight tube through an input opening and exit through an output opening. The stage supports a sample object to receive neutrons that pass through the entire length of the flight tube and the output opening. The neutron imaging module has a neutron-sensitive component that receives neutrons that pass through the sample object and generates neutron detection signals. The neutron shield surrounds at least a portion of the flight tube and the neutron imaging module to block at least a portion of stray neutrons that travel toward the neutron-sensitive component of the neutron imaging module, in which the stray neutrons do not enter the flight tube through the input opening of the flight tube.
A channel electron multiplier having a high aspect ratio and differential coatings along its channel length is disclosed. The elongated tube has an input end, an output end, and an interior surface extending along the length of the tube between the input end and the output end. The channel electron multiplier also has first and second conductive layers formed on the interior surface of the tube. The first conductive layer is selected to provide a first electrical resistance, a first electron emission characteristic, or both, and the second conductive layer is selected to provide a second electrical resistance, a second electron emission characteristic, or both. A method of making a channel electron multiplier having two or more different conductive layers is also disclosed.
A method for detecting a neutron includes providing a first voltage to an input electrode of a microchannel plate, providing a second voltage to an output electrode of the microchannel plate, the second voltage being more positive than the first voltage, measuring a signal on the output electrode, and detecting a neutron based on a comparison of the signal at the output electrode with a baseline value.
A neutron detector includes a microchannel plate having a structure that defines a plurality of microchannels, and layers of materials disposed on walls of the microchannels. The layers include a layer of neutron sensitive material, a layer of semiconducting material, and a layer of electron emissive material. For example, the layer of neutron sensitive material can include at least one of hafnium (Hf), samarium (Sm), erbium (Er), neodymium (Nd), tantalum (Ta), lutetium (Lu), europium (Eu), dysposium (Dy), or thulium (Tm).
H01L 31/08 - SEMICONDUCTOR DEVICES NOT COVERED BY CLASS - Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
G01T 3/08 - Measuring neutron radiation with semiconductor detectors
A device includes a neutron-sensitive composition. The composition includes, in weight percent, a non-zero amount of aluminum oxide (e.g., approximately 1% to approximately 3.5% aluminum oxide), greater than 12% (e.g., approximately 12% to approximately 17%) boron oxide, greater than approximately 60% silicon oxide (e.g., approximately 62% to approximately 68% silicon oxide), and a non-zero amount of sodium oxide (e.g., approximately 10% to approximately 14% sodium oxide). The device is capable of interacting with neutrons to form an electron cascade.
A method for detecting a neutron includes providing a first voltage to an input electrode of a microchannel plate, providing a second voltage to an output electrode of the microchannel plate, the second voltage being more positive than the first voltage, measuring a signal on the output electrode, and detecting a neutron based on a comparison of the signal at the output electrode with a baseline value.
A neutron detector includes a microchannel plate having a structure that defines a plurality of microchannels, and layers of materials disposed on walls of the microchannels. The layers include a layer of neutron sensitive material, a layer of semiconducting material, and a layer of electron emissive material. For example, the layer of neutron sensitive material can include boron-10, lithium-6, or gadolinium.
H01L 31/0352 - SEMICONDUCTOR DEVICES NOT COVERED BY CLASS - Details thereof characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
10.
Neutron detection based on energy spectrum characteristics
A neutron detector includes a coincidence detector to detect coincidence events in which each coincidence event indicates proximity in time of a first signal and a second signal. The first signal indicates detection of at least one of a neutron or a gamma ray, and the second signal indicates detection of a gamma ray by a gamma ray detector. A data processor identifies detection of neutron radiation based on characteristics of an energy spectrum of the gamma rays associated with the second signals that correspond to the coincidence signals.
A neutron detector includes a microchannel plate having a structure that defines a plurality of microchannels, and layers of materials disposed on walls of the microchannels. The layers include a layer of neutron sensitive material, a layer of semiconducting material, and a layer of electron emissive material. For example, the layer of neutron sensitive material can include boron-10, lithium-6, or gadolinium.
Neutrons can be detected using first information derived from a first charge induced on an input electrode of a microchannel plate and second information derived from a second charge induced on an output electrode of the microchannel plate. For example, a ratio between the first charge and the second charge is calculated, a sum of the first and second charges is calculated, and whether a neutron has been detected can be determined based on the ratio and the sum.
In exemplary embodiments, an apparatus, includes a first electrode, a second electrode, a first polygonal channel extending between the electrodes, the first channel having a first side having a center, and a second polygonal channel extending between the electrodes, the second channel having a second side contacting the first side, the second side having a center, wherein the center of the first side and the center of the second side are non-collinear in a direction perpendicular to a surface of the first side, and wherein the first and second channels do not have square cross sections perpendicular to longitudinal axes of the channels.
A device includes a neutron-sensitive composition. The composition includes, in weight percent, a non-zero amount of aluminum oxide (e.g., approximately 1% to approximately 3.5% aluminum oxide), greater than 12% (e.g., approximately 12% to approximately 17%) boron oxide, greater than approximately 60% silicon oxide (e.g., approximately 62% to approximately 68% silicon oxide), and a non-zero amount of sodium oxide (e.g., approximately 10% to approximately 14% sodium oxide). The device is capable of interacting with neutrons to form an electron cascade.
A reflectron lens for a time-of-flight mass spectrometer and a method of making same are disclosed. The reflectron lens includes a glass tube having a conductive surface along the length of the tube. The conductive surface has an electrical resistance gradient along its length. The electrical resistance gradient provides an electric field interior to the tube that varies in strength along the length of the tube when an electric potential is applied to opposing ends of the tube. A mass spectrometer incorporating the reflectron lens, a method of making the reflectron lens, and an apparatus for removing lead from the surface of a lead silicate glass tube are also disclosed.
In some embodiments, an electron multiplier includes a neutron-sensitive composition having, in weight percent, approximately 30% to approximately 60% silicon oxide, approximately 20% to approximately 60% lead oxide, and approximately 1% to approximately 15% boron-10 enriched boron oxide. The composition is capable of interacting with neutrons to form an electron cascade. The electron multiplier can be in the form of a microchannel plate, a microfiber plate, or a microsphere plate.
An arrangement for a MALDI sample plate for ion mass spectroscopy is disclosed. The sample is configured to shape the hypersonic explosion which creates the ions generated in a MALDI-type time-of-flight mass spectrometer. The MALDI sample plate includes a glass wafer formed from a plurality of clad glass fibers and has a first planar surface. The plate also has a plurality of micro-wells formed in the glass wafer. The micro-wells extend to a depth that is less than the thickness of the glass wafer and act to hold a spot sample in a manner that prevents spreading, maximizes the formation of ions, and shapes the resulting ion cloud to improve ion migration.
A microchannel plate and a method of making same are disclosed. The microchannel plate has an active area and at least one solid glass pad. The active area has a plurality of microchannels formed therein. The solid glass pad or pads are formed within the active area, and preferably at peripheral locations, for mounting the microchannel plate. With this arrangement, shrinkage of the microchannel plate during fabrication and hydration induced swelling of the active area after fabrication of the microchannel plate do not result in catastrophic warping or cracking of the microchannel plate.
A detector for a coaxial bipolar time-of-flight mass spectrometer is described. The detector includes a microchannel plate, a scintillator disposed in parallel relation to said microchannel plate, and a mirror oriented at an angle relative to said scintillator. The angle of the mirror is selected to reflect photons given off by the scintillator in a direction substantially orthogonal to the scintillator. The microchannel plate, the scintillator, and the mirror each have an opening formed centrally therein. The detector according to this aspect of the invention also includes a transparent tube extending through the central openings formed in each of the microchannel plate, the scintillator, and the mirror. A photomultiplier tube is coupled to the detector for receiving photons reflected by the mirror. A coaxial bipolar time-of-flight mass spectrometer incorporating the detector is also described.
