62 results about "Compton scattering" patented technology

The invention discloses a pole piece surface density measurement method based on a double-index model, which comprises the following steps: firstly, starting an X-ray source, and measuring the ray intensity when a pole piece is not placed; secondly, replacing standard to-be-measured pole pieces with different surface densities, and measuring ray intensity; obtaining mass attenuation coefficients corresponding to different coating surface densities according to an attenuation formula, and performing double-index model correction on the mass attenuation coefficients according to the calibration data; and finally, measuring the intensity of rays passing through the pole piece to be measured, and measuring the surface density of the pole piece according to a ray intensity attenuation model and the calibrated mass attenuation coefficient. According to the method, the surface density of the pole piece is measured by using a method for correcting the quality attenuation coefficient of the pole piece through the double-index model, and compared with a method for directly calibrating the measured ray intensity and the standard surface density value, the problem that the measurement of the surface density of the pole piece coating is affected by X-ray beam hardening and Compton scattering is solved; and the surface density measurement precision of the pole piece is improved.

The invention relates to a femtosecond gamma ray pulse generation device, which comprises a femtosecond order electron beam slice generation system, a cavity, a Compton scattering laser system and collimation equipment, and is characterized in that the femtosecond order electron beam slice generation system, the cavity and the collimation equipment are sequentially arranged along a first axis; the femtosecond-order electron beam slicing system is used for generating femtosecond-order electron beams with high-density slices, the cavity is used for providing an interaction cavity, and the Compton scattering laser system is used for generating pulse type laser. The pulse type laser and the electron beam with the high-density slices in the femtosecond order are subjected to Compton scattering in the interaction cavity so as to generate a gamma-ray pulse in the femtosecond order; the collimation device is used for carrying out collimation on the femtosecond order gamma ray pulse.

The invention relates to a method for detecting boron distribution in an oxidation corrosion product deposition layer. The total mass of boron in the oxidation corrosion product deposition layer is detected by utilizing an instantaneous gamma activation technology; the method comprises the following steps: obtaining a geometric boundary of a deposition layer of a corrosion product according to neutron photography, constructing a Compton cone in the geometric boundary obtained by neutron photography according to instant gamma rays generated by the oxidation corrosion product and Compton scattering information generated by the action of a Compton photography unit, and reconstructing the origin of the gamma rays; and carrying out pixelated image reconstruction by adopting a random origin set algorithm to obtain a distribution image generated by gamma rays so as to obtain the proportional distribution of the boron element in the oxidation corrosion product deposition layer. According to the obtained total boron element concentration and boron element proportion distribution, boron element concentration distribution in the oxidation corrosion product deposition layer is calculated, and the defects that only boron element distribution in the limited depth of the surface of the corrosion product deposition layer can be measured and internal element distribution information cannot be obtained in an existing method are overcome.

Measured and selected scattered photons from an X-ray imaging acquisition are used to better characterize the X-rayed object and / or to generate a scattering image. Scattering-based X-ray images are generated using a measure of scattered photons from an X-ray absorption acquisition and are used to determine the scattering index of the scanned object. This information can be used to determine the nature of the scanned object and to better understand its structures. Such information is derived from a conventional X-ray absorption scan. The presented improvements and advantages are achieved using information provided by time-of-flight measurements of scattered (non-ballistic) photons that allow to determine an ellipse of possible scattering positions, the shape of which is determined from the corresponding time-of-flight. The proposed method and apparatus are used to generate scattering images and to characterize additional properties of scanned objects, which can be combined or used complementarily to conventional X-ray absorption scans.

A volumetric radiation dose detector provides radiation sensors distributed along plates of a laminated stack, the stack comprising materials having different Compton scattering such that the stack has water equivalence. The plate configuration allows for convenient adjustment of the spacing between photodetectors to provide different resolutions across the entire area and depth of the detector. Printed circuit technology may be used to produce a board holding a photodetector for simplified signal management.

To solve a problem in which the other radiations may arrive at a radiation detector and the usefulness of data regarding the other radiations is lower than the usefulness of data of Compton scattering.SOLUTION: A detection device for detecting radiations comprises: a container for housing gas; an electronic detector that is positioned inside the container and generates an analog signal by detecting electrons generated by Compton scattering; a drift electrode that opposes the electronic detector; a radiation detector for generating an analog signal by detecting radiations scattered by Compton scattering; a first read circuit for digitizing the analog signal generated by the radiation detector, generating first data, and storing the first data in a first buffer; and a second read circuit for digitizing the analog signal generated by the electronic detector and generating second data. The first read circuit transmits first final data including the first data stored in the first buffer to an external computer according to a first trigger signal.SELECTED DRAWING: Figure 1

The invention discloses a background deduction and signal correction method for an XRF spectrum of food. The background deduction and signal correction method comprises the following steps: step 1, selecting pure glucose as a standard background substance; step 2, performing low-voltage background deduction; 3, deducting a high voltage background; step 4, signal correction: selecting an internal standard signal: selecting a Ka line Compton scattering peak area of Ag measured under high voltage as the internal standard signal; and performing normalization processing: dividing the characteristic X-ray peak area SElementi of each element to be detected after the background is deducted by the Ka-line Compton scattering peak area AgKaCompton of the Ag to obtain the peak area after Compton normalization. According to the background deduction and signal correction method and system for the XRF spectrum of the food provided by the invention, signal intensity fluctuation caused by measurement gap change can be effectively compensated. Background deduction is accurate, the anti-interference capability is high, the universality is good, and the detection lower limit can be effectively improved.

Some embodiments of the present disclosure provide a method that includes colliding a laser with an electron beam to produce backscattered x-rays while the electron beam is traversing a circular arc. This backscattering process is inverse Compton scattering (ICS). ICS x-rays are emitted in the same direction as the electrons. Because this ICS direction is changing as a function of time, the position of the x-ray beam on a detector will change depending on the timing of electron / laser collision. This position change is easily detected and converted to a timing measurement sensitive at the femtosecond scale, converting a very difficult timing measurement of laser pulse, electron pulse, and x-ray pulse synchronization into a simple and robust position measurement.

Some embodiments of the present disclosure provide a method that includes colliding a laser with an electron beam to produce backscattered x-rays while the electron beam is traversing a circular arc. This backscattering process is inverse Compton scattering (ICS). ICS x-rays are emitted in the same direction as the electrons. Because this ICS direction is changing as a function of time, the position of the x-ray beam on a detector will change depending on the timing of electron / laser collision. This position change is easily detected and converted to a timing measurement sensitive at the femtosecond scale, converting a very difficult timing measurement of laser pulse, electron pulse, and x-ray pulse synchronization into a simple and robust position measurement.

An X-ray fluorescence spectrometer (10) includes: a sample stage (2); an X-ray tube (7) that radiates excitation X-rays toward the sample stage (2); a detector (8) that detects fluorescent X-rays emitted from a sample on the sample stage; and a control device (14) that controls the X-ray tube (7) and the detector (8). Assuming that an intensity of X-rays that are part of the fluorescent X-rays, of a material of an X-ray tube target, emitted from the X-ray tube (7) and are Rayleigh scattered by the sample(S) placed on the sample stage (2) is defined as IR and that an intensity of X-rays that are Compton scattered is defined as IC, when the control device (14) creates a calibration curve by irradiating the standard sample with the excitation X-rays from the X-ray tube (7) and when a value of IR / IC obtained for the standard sample is out of a reference range, the control device (14) issues a warning.

The present invention provides a high-repetition-rate extreme ultraviolet radiation light source and an EUV lithography machine light source, wherein a portion of the target laser pulses is incident on a megawatt-class optical gain cavity to generate a second infrared laser pulse with a megawatt average power; another portion of the target laser pulses is incident on a room-temperature very high frequency photocathode microwave electron gun after frequency doubling and shaping, driving the room-temperature very high frequency photocathode microwave electron gun to generate a continuous picosecond electron beam with a repetition rate of hundreds of megahertz; the continuous picosecond electron beam is incident on the megawatt-class optical gain cavity and undergoes inverse Compton scattering with the second infrared laser pulse to generate radiation in the extreme ultraviolet band; further, by adjusting the energy of the continuous picosecond electron beam and the laser incident angle, the wavelength of the scattered light can be adjusted within a certain range, thereby realizing a high-repetition-rate extreme ultraviolet radiation light source.

An image capture device 1A comprises a measuring unit 10 and a processing unit 20. The processing unit 20 determines, for each coincidence event in which a first detector 11 and a second detector 12 perform coincidence detection of a pair of gamma-ray photons generated by an electron-positron annihilation event in a positron-emitting radionuclide 81, a position at which the gamma-ray photon is Compton-scattered in the object 90, assuming that the gamma-ray photon arriving at one detector of the first detector 11 and the second detector 12 is a gamma-ray photon arriving without Compton scattering in an object 90, and the gamma-ray photon arriving at another detector is a gamma-ray photon arriving after being Compton-scattered in the object 90.based on a detection position and a detection time of the gamma-ray photon by each of the first detector 11 and the second detector 12 and a position of the positron-emitting radionuclide 81. In this way, an image acquisition device and an image acquisition method capable of acquiring a tomographic image representing anatomical information of an object without performing image reconstruction processing are realized.

An image acquisition apparatus includes a measurement unit and a processing unit. The processing unit, for each coincidence event in which a first detector and a second detector perform coincidence detection of a pair of gamma-ray photons generated by an electron positron annihilation event in a positron emitting radionuclide, assuming that the gamma-ray photon arriving at one detector is a gamma-ray photon arriving without being Compton scattered in a subject, and the gamma-ray photon arriving at another detector is a gamma-ray photon arriving after being Compton scattered in the subject, determines a position at which the gamma-ray photon is Compton scattered in the subject based on a detection position and a detection time of the gamma-ray photon by each of the first detector and the second detector and a position of the positron emitting radionuclide.

A medical imaging apparatus based on gamma-ray detection includes a detector and circuitry. The detector includes a plurality of detector modules. Each detector module is divided into N light-sharing segments, and each light-sharing segments covers M photosensors. The circuitry includes (1) a plurality of sets of M first-level electronic units and (2) a second-level electronic unit. Each set of M first-level electronic units reads the electrical signals generated by of a corresponding one of the plurality of detector modules. For each detector module, each first-level electronic unit of a corresponding set of M first-level electronic units reads the electrical signals generated by N photosensors, in a multiplexing manner, to generate timing, energy, and position readout signals on a single set of readout channels. The second-level electronic unit processes the timing, energy, and position readout signals output from M sets of readout channels of the set of M first-level electronic units.

A high-resolution Compton gamma camera, relating to the technical field of gamma measurement, and comprising: a high-gas-pressure tank (1) provided with a window (2), a metal film (3) being sealedly provided at the window (2), and a plurality of flange interfaces (4) being formed on the side wall or the bottom of the high-gas-pressure tank (1); a time projection chamber detector (5) which is provided in the high-gas-pressure tank (1) and is used for implementing gamma ray Compton scattering conversion and three-dimensional trajectory and energy measurement of scattered electrons; and a gamma calorimeter (6) which is located between a field cage of the time projection chamber detector (5) and the inner wall of the high-gas-pressure tank (1) and is used for implementing position and energy measurement of Compton scattered gamma and electron leakage. The camera implements high-precision measurement of Compton scattered electrons and gamma, and accurate measurement of the gamma direction and energy, providing key technical support for applications such as astronomical observation and radiation therapy.

The invention provides a gamma camera based on a gas detector and a reconstruction method, the gamma camera comprises a gas time projection chamber detector and five groups of crystal energy meters, and the crystal energy meters are distributed on five side surfaces of the gas time projection chamber detector; after gamma incidence, Compton scattering occurs in working gas of the detector, particle tracks of scattered electrons are recorded by the detector, and the position of a Compton action vertex and the direction and energy of the scattered electrons can be reconstructed; the scattered photons are detected by a crystal energy meter on the side wall, the connecting line of the position detected by the crystal energy meter and a Compton action point is the direction of scattered photons, and energy collected by the crystal energy meter can reconstruct the momentum of the scattered photons; based on the momentum of scattered electrons and photons, the direction of incident gamma photons can be reconstructed. According to the gamma camera design, imaging information of five dimensions of three-dimensional position, time and energy is provided, and the imaging capability of the gamma camera is greatly improved.

The application discloses a kind of solar flare X-ray full-link simulation method and system based on Geant4, belong to space satellite detection and numerical simulation technical field.The method includes: build high-performance hybrid parallel computing platform based on Geant4;Based on the platform, construct layered magnetized solar atmosphere model, configure physical process list and generate high-energy electron particle source;Through light tracing algorithm and self-defined step action module, the transmission, scattering and polarization evolution of X-ray in layered magnetized solar atmosphere are tracked and simulated;Through pixelated imaging and data output module, photon information is mapped to multiple virtual detector imaging planes, and X-ray imaging, energy spectrum and polarization degree data of different observation angles are output.The application solves the problems of existing model and multi-satellite stereoscopic observation data mismatch, Compton scattering details missing, polarization information deficiency and low computing efficiency, and provides an effective tool for analysis and simulation of multi-satellite joint observation data.

A detection device for detecting radiation includes: a container in which a gas is accommodated; the electron detector is positioned in the container, detects electrons generated by Compton scattering, and generates an analog signal; a drift electrode facing the electron detector; a radiation detector that detects radiation scattered by Compton scattering and generates an analog signal; a first readout circuit that digitizes the analog signal generated by the radiation detector, generates first data, and stores the first data in a first buffer; and a second readout circuit that digitizes the analog signal generated by the electron detector and generates second data. The first readout circuit transmits first final data including the first data stored in the first buffer to an external computer according to the first trigger signal.

The invention discloses a Compton scattering imaging device based on focusing collimation and a defect detection method. The Compton scattering imaging device comprises a ray source used for generating X-rays or gamma-rays with certain energy and angle distribution; the front collimator is used for collimating rays output by the ray source to form a beam to perform point-by-point scanning on a measured object; the rear collimator with the focusing structure is formed by splicing a plurality of focusing collimation structures which are distributed and arranged, effective light-passing axes of the focusing collimation structures are converged in the same focusing area, and the rear collimator with the focusing structure is used for receiving scattering signals generated in the effective light-passing axis direction within the range of the focusing area with the set depth of the measured object; the focusing area covers the scanning point; the large-area detector is used for receiving the scattering signal output by the rear collimator and converting the scattering signal into an analog electric signal; and the electronics acquisition system is used for receiving the analog electric signal, converting the analog electric signal into a digital signal, processing the digital signal and transmitting the processed digital signal to the upper computer to generate an internal structure image of the measured object. According to the invention, the spatial resolution capability is greatly improved.

The invention discloses a wall hollowing detection method based on Geant4 and Compton back scattering, and relates to the technical field of nondestructive testing, structural design and optimization are carried out by utilizing a Monte Carlo program Geant4 widely applied to the nuclear field, and Compton scattering is carried out between high-energy rays and substances in a wall after the high-energy rays are simulated to be emitted to the wall through the Geant4; the energy and intensity of scattered photons carry information of the internal structure of the wall body, and scattered signals can change at the hollowing position; the position and the size of the hollowing can be determined by analyzing the energy, the intensity and the spatial distribution of the back scattering signal received by the detector, so that the nondestructive detection of the hollowing in the wall body is realized; and the parameters in the detection process can be adjusted according to the detection result until the parameter setting with a better detection effect is obtained.

The invention discloses a Geant4-based solar flare X-ray full-link simulation method and system, and belongs to the technical field of space satellite detection and numerical simulation. The method comprises the following steps: building a Geant4-based high-performance hybrid parallel computing platform; a layered magnetization solar atmosphere model is constructed based on the platform, a physical process list is configured, and a high-energy electron particle source is generated; through a ray tracing algorithm and a user-defined stepping action module, tracking simulation is carried out on transmission, scattering and polarization evolution of X-rays in the layered magnetized solar atmosphere; and through a pixelated imaging and data output module, the photon information is mapped to imaging planes of a plurality of virtual detectors, and X-ray imaging pictures, energy spectrums and polarization degree data of different observation visual angles are output. The problems that an existing model is not matched with multi-satellite stereoscopic observation data, Compton scattering details are missing, polarization information is insufficient and calculation efficiency is low are solved, and an effective tool is provided for analysis and simulation of multi-satellite combined observation data.

An image acquisition device (1A) is provided with a measurement unit (10) and a processing unit (20). For each coincidence counting event, that is, an event in which a pair of gamma-ray photons generated by an electron-positron pair annihilation event in a positron emission nuclide (81) is counted simultaneously by a first detector (11) and a second detector (12), a processing unit (20) has gamma-ray photons arriving at the second detector (12) after Compton scattering occurs within a subject (90). When the signal output by the first detector (11) and the signal output by the second detector (12) are lower than a first threshold value lower than 511 keV, the position of the positron emission nuclide (81) is detected selectively on the basis of the detection position and the detection time of the gamma ray photons and the position of the positron emission nuclide (81), respectively, detected by the first detector (11) and the second detector (12), and the position of the positron emission nuclide (81) is lower than a first threshold value lower than 511 keV. The position at which Compton scattering occurs in the subject (90) of the gamma ray photons is determined. This realizes an image acquisition device and an image acquisition method that can acquire a tomographic image representing anatomical information of a subject without performing image reconstruction processing.

A method for detecting the distribution of boron in the oxidation corrosion product deposition layer, using the prompt gamma activation technology to detect the total mass of boron elements inside the oxidation corrosion product deposition layer; according to the neutron radiography to obtain the geometric boundary of the corrosion product deposition layer, according to the Compton scattering information generated by the interaction of the prompt gamma rays generated by the oxidation corrosion product and the Compton radiography unit, the Compton cone is constructed within the geometric boundary obtained by neutron radiography, the origin of the gamma ray is reconstructed, and the pixelized image reconstruction is carried out by using the random origin set algorithm, the distribution image generated by the gamma ray is obtained, and the proportional distribution of the boron element in the oxidation corrosion product deposition layer is obtained. According to the obtained total concentration of boron element and the proportional distribution of boron element, the concentration distribution of boron element in the oxidation corrosion product deposition layer is calculated, which improves the existing method which can only measure the distribution of boron element in the limited depth of the surface of the corrosion product deposition layer and cannot obtain the internal element distribution information.

The invention relates to a back scattering imaging detection device. The device comprises a radioactive source used for generating gamma rays; irradiating the surface of the to-be-measured object with the gamma rays to form Compton scattering gamma rays; the first detection unit is used for acquiring imaging position information; the second detection unit is used for acquiring imaging energy information; the signal processing unit is used for receiving the imaging position information and the imaging energy information; and the image reconstruction unit is electrically connected with the signal processing unit and is used for carrying out data processing and image reconstruction on the received information. According to the invention, the Na-22 radioactive source is used as a light source to generate gamma rays, so that the thickness of a detectable sample is increased; the device is convenient to use, the position, pose and other information of the device are easy to record or grasp, inconvenience caused by long-time continuous use of the detection device is reduced, the detection units with the same or different resolution precision can be replaced according to needs, and the device has the advantages of miniaturization, good portability and high detection precision and can be used under various complex working conditions.

A neutron flux detector comprising a source material and a solid state radiation detector is disclosed. The source material is configured to produce gamma photons greater than or equal to 6.8 MeV during neutron capture. The solid state radiation detector comprises a Schottky diode and an emitter layer comprising a Compton and photoelectron source material. The emitter layer is configured to receive the gamma photons produced by the source material. The emitter layer is spaced apart from the Schottky diode a distance such that a gap is defined between the emitter layer and the Schottky diode. The distance is selected such that only electrons produced by the emitter layer as a result of the emitter layer absorbing the gamma photons will contribute to a measured output signal of the Schottky diode.

An image acquisition device (1A) is provided with a measurement unit (10) and a processing unit (20). The processing unit (20) performs simultaneous counting of a pair of gamma-ray photons generated by pair annihilation of electrons / positron in the positron emission nuclide (81) by the first detector (11) and the second detector (12). Gamma-ray photons coming to one of the first detector (11) and the second detector (12) are photons coming without Compton scattering in the subject (90), and gamma-ray photons coming to the other of the first detector (11) and the second detector (12) are photons coming after Compton scattering in the subject (90). The position at which Compton scattering occurs in the subject (90) of the gamma-ray photons is determined on the basis of the position of the positron emission nuclide (81) and the detection position and the detection time of the gamma-ray photons obtained by the first detector (11) and the second detector (12), respectively. As a result, it is possible to obtain a tomographic image representing anatomical information of a subject without performing image reconstruction processing, and to obtain an image acquisition method.

The invention discloses a gamma ray energy spectrum and polarization degree integrated measurement method, and belongs to the technical field of gamma ray measurement. The method comprises the following steps: firstly, acquiring a spatial distribution measurement result of scattered gamma rays generated by Compton scattering of to-be-measured gamma rays, and then determining a response function between the energy spectrum and the polarization degree of the gamma rays and the spatial distribution of the scattered gamma rays, so as to determine the spatial distribution of the scattered gamma rays according to the spatial distribution measurement result and the response function; and constructing an equation set between the energy spectrum and the polarization degree of the to-be-measured gamma ray and the spatial distribution measurement result, and solving the equation set to obtain the energy spectrum and the polarization degree of the to-be-measured gamma ray. According to the method, the energy spectrum and the polarization degree of the to-be-measured gamma ray can be rapidly, accurately, indirectly and simultaneously measured through reverse calculation only by acquiring the spatial distribution measurement result of the scattered gamma ray generated by the Compton scattering of the to-be-measured gamma ray.

This application provides a method for adjusting the divergence angle of an electron beam, a method and apparatus for adjusting the field of view of an all-optical inverse Compton scattering source, relating to the fields of laser wake accelerators and light source technology. The method for adjusting the electron beam divergence angle includes: generating an electron beam and adjusting the initial transverse phase space distribution of the electron beam; adjusting the evolution of the transverse phase space of the electron beam to adjust the divergence angle of the electron beam. This application adjusts the electron beam divergence angle at the point of beam generation by adjusting the initial transverse phase space distribution and the evolution process of the transverse phase space of the electron beam generated by the laser wake accelerator, thereby achieving field-of-view adjustment of the all-optical inverse Compton scattering source.

A method of determining material composition of a target includes identifying a component of the material composition of the target by matching a Compton scattering background, in a spectrum of detected X-rays acquired by irradiating the target with a source of X-rays during a nominal source exposure time period, to a Compton scattering spectrum for the component; and reporting the material composition of the target including the identified component of the material composition.

The invention discloses a GPU (Graphics Processing Unit) parallel Monte Carlo light atom reaction sampling method, which comprises the following steps of: firstly, calculating a probability density function of scattering angle cosine based on a coherent scattering and Compton scattering differential section formula, and carrying out trapezoidal integration on the probability density function of the scattering angle cosine to obtain a probability distribution function of the scattering angle cosine; secondly, calculating probability distribution functions under all incident energy points to obtain a two-dimensional interpolation table of the probability distribution functions about incident energy and scattering angle cosine; and finally, sampling the scattering angle cosine in a Monte Carlo particle transport program, and calculating the energy of the secondary photons according to a sampling result. According to the GPU parallel Monte Carlo light atom reaction sampling method provided by the invention, the GPU parallel efficiency is greatly improved.