56 results about "Alpha particle" patented technology

The invention discloses an ionization chamber internal electric field modeling and radioactive interference suppression method. The method comprises the following steps: modeling by adopting a multi-physical simulation software package to obtain a geometric model of an ionization chamber; analyzing electric field distribution in the ionization chamber through finite element analysis software, and simulating a plurality of parameters by adopting a particle physical experiment simulation program to set a drift trajectory and a drift end point of secondary electrons so as to obtain ionization chamber parameters meeting conditions; and optimizing the ionization gas chamber according to the ionization gas chamber parameters meeting the conditions, and monitoring and outputting particle drift and current induction results based on the optimized ionization gas chamber. The radiation interference caused by the detector can be shielded on the basis of the original functions of the traditional ionization gas chamber, and the background emissivity of the alpha particle measuring device is reduced, so that the detection efficiency and accuracy of low-level radioactive measurement are improved.

The invention provides a GaN-based alpha particle detector and a preparation method thereof, the GaN-based alpha particle detector comprises a substrate and an epitaxial structure epitaxially formed on the substrate, and the epitaxial structure comprises a multi-quantum well layer. A multi-quantum well layer is introduced, the multi-quantum well layer absorbs incident energy of alpha particles and correspondingly excites a large number of electron-hole pairs, and the electron-hole pairs are limited in quantum wells by the quantum confinement effect of the multi-quantum well layer, so that not only is the loss of electron-hole pair diffusion and recombination reduced, but also the service life of current carriers is prolonged, and the performance of the device is improved. The carrier collection efficiency of the alpha particle detector is greatly improved, and more electron-hole pairs can be collected and converted into electric signals to be output, so that the performance of the alpha particle detector is improved.

The invention relates to alpha particle measurement equipment, method and device, a storage medium and a program product. The equipment is formed by surrounding a side wall of the equipment, a cavity top and a cavity bottom; a collector and a cathode are arranged in the cavity; the collector is arranged at the top of the cavity; the cathode is arranged at the bottom of the cavity; the collector is parallel to the cathode; the distance between the collector and the cathode meets a first preset distance; the collector comprises a plurality of first anode wires laid along a first direction and a plurality of second anode wires laid along a second direction; the distance between each first anode wire and each second anode wire in the third direction is a second preset distance, the distance between two adjacent first anode wires in the first direction is a third preset distance, and the distance between two adjacent second anode wires in the second direction is a fourth preset distance. By adopting the method, the accuracy of alpha particle measurement results can be improved.

The invention discloses a compensation method and system for continuously, rapidly and accurately measuring the radon concentration in air, and the method comprises the steps: taking the number of nuclides in a measurement cavity at the initial moment of a current sampling period as an initial value, and obtaining a time-varying function of the number of nuclides in the measurement cavity in combination with a gas exchange and nuclide decay model; determining the theoretical total count of alpha particles in the current measurement period, and establishing a relational expression between the count of the alpha particles and the number of nuclides; based on the relational expression and the actual measurement count, the number of environmental radon atoms is obtained, and the radon concentration is calculated in combination with a radon decay constant; and finally, combining the number of radon atoms at the current sampling point and a model containing gas exchange and nuclide decay to obtain the nuclide number at the end of sampling, taking the nuclide number as the initial state of the next sampling period, switching the sampling points, and repeating the steps to realize continuous, rapid and accurate sampling. According to the method, through loop iteration, the balance waiting time is effectively saved, and continuous, rapid and accurate measurement of the radon concentration in the environment by a single radon measuring instrument is realized.

The invention discloses a radon gas detector test method and related equipment, and the method comprises the steps: obtaining equipment parameters of a tested radon gas detector, and determining the first test concentration of the tested radon gas detector according to the equipment parameters; determining the test distance of the radon gas detector to be tested according to the first test concentration, wherein the first test concentration is in negative correlation with the test distance; controlling the distance between the americium 241 radioactive source and the detected radon gas detector to meet the test distance, and controlling the americium 241 radioactive source to be turned on; acquiring a plurality of first test data acquired by the signal transceiving module from the radon gas detector to be tested during the starting period of the americium 241 radioactive source, wherein the first test data are electric signal data corresponding to alpha particles generated by the americium 241 radioactive source; and determining a test result of the tested radon gas detector according to the plurality of first test data. By adopting the method provided by the invention, the problem of high detection cost caused by a radon source in a traditional detection method is solved.

A system includes one or more neutron sources configured to emit neutrons. The system also includes one or more electron detectors configured to detect electrons. Further, the system includes a control system comprising one or more processors. The control system is configured to determine a lithium concentration based on the electrons. Further, the control system is configured to generate a lithium extraction output based on the lithium concentration.

This invention relates to the field of neutron source technology, and particularly to a controllable isotope neutron source device based on ion migration and a method for generating neutrons. The device includes a casing, inside which are a target material module, a target ion migration system, a safety module, and an alpha particle source term. The target material module provides target nuclide ions. The alpha particle source term includes alpha radioactive nuclide material and target nuclide intercalation material. The safety module is composed of target nuclide intercalation material. The target ion migration system is connected to an external control field. Target nuclide ions migrate through the target ion migration system within the safety module and the alpha particle source term. This invention enables active controllability of the isotope neutron source, significantly improving safety. By ensuring sufficient contact between alpha particles and target nuclides to form a molecular intercalation structure, the (α,n) reaction efficiency is greatly improved. Furthermore, this neutron source can be used in combination with multiple modules according to application requirements, effectively increasing the neutron output flux.

The present invention discloses a system and method for measuring the deuterium-tritium fuel ratio in plasma, comprising an electron cyclotron radiometer, a microwave reflectometer, a Mirnov probe, electron cyclotron radiation imaging, a first collector, a central processing unit, an interferometer, a dynamic Stark effect spectrometer, a magnetic coil, a charge exchange spectrometer, a second collector, a high-performance computer, and a TAE frequency real-time processor. The deuterium-tritium fuel ratio can be obtained by accurately measuring the frequency of the toroidal Alfvén eigenmode in the burning plasma and accurately calculating the TAE frequency in the deuterium-deuterium plasma under the same conditions. Compared to the existing technology, even if the burning plasma is in an uneven distribution state, it can be measured as a whole, and the deuterium-tritium fuel ratio can be calculated based on the measured data, thereby providing a safe, accurate, and rapid method for measuring the deuterium-tritium fuel ratio for the heating effect of fusion product alpha particles, the high and low confinement mode conversion power thresholds, and the confinement time.

The application provides a fuel and a method for increasing the neutron source intensity of a nuclear reactor, wherein the abundance of O in the fuel is 1% to 50% 18 O is 1% to 50%, and alpha particles and the enriched 18 O can significantly enhance the initial neutron source intensity of a nuclear reactor core in a pressurized water nuclear power plant, and help to improve the start-up performance and reduce the dependence on external neutron sources. In the passive start-up mode without using an external neutron source, the application improves the isotope abundance of O in the fuel, and improves the (alpha, n) reaction neutron source in the nuclear reactor core in the pressurized water nuclear power plant. 18 O in the fuel, and improves the isotope abundance of O in the fuel, and improves the (alpha, n) reaction neutron source in the nuclear reactor core in the pressurized water nuclear power plant.

The present invention relates to a high counting rate alpha particle detection method for accompanying particle imaging of a fusion neutron generator, which can effectively improve the measurement counting rate and timing accuracy of the accompanying particle imaging system of a fusion neutron source. The method comprises: by setting a barrier layer of a semiconductor detector, the thickness of a detection sensitive area, and thinning the thickness of an electrode and a substrate, the energy deposition of interference particles in a deuterium-tritium neutron source in the sensitive area of ​​the detector is reduced, and the proportion of energy deposition of accompanying alpha particles in the sensitive area of ​​the detector is increased, so that the amplitude of the current pulse signal output by the detector is proportional to the particle deposition energy; a current sensitive amplifier is used to amplify and reduce noise on the pulse signal output by the detector, and a narrow width voltage signal proportional to the current signal of the detector is output; a leading edge timing discriminator is used to time the pulse leading edge of the amplified voltage signal, and a reasonable trigger threshold is set to eliminate interference particle signals, so that only accompanying alpha particle timing signals are obtained.

The invention belongs to the field of neutron tubes, and particularly relates to an alpha particle accompanying neutron tube for security check and a region measurement method based on the neutron tube. The neutron tube comprises a tube shell assembly, an ion source assembly, an acceleration collimation assembly, a deuterium tritium target assembly, a storage and an alpha particle detector, the ion source assembly is mounted at the upper end in the tube shell assembly; the acceleration collimation assembly is installed in the tube shell assembly and located on an output path of the ion source assembly. The deuterium tritium target assembly is installed at the lower end in the tube shell assembly and located on an output path of the acceleration collimation assembly. The storage device is installed at the lower end in the tube shell assembly. A mounting opening is formed in the lower end of the side wall of the tube shell assembly, the alpha particle detector is mounted at the mounting opening of the tube shell assembly, and the receiving surface of the alpha particle detector faces the target surface of the deuterium-tritium target body. According to the invention, the flight direction of neutrons can be determined by detecting the accompanying alpha particles, so that the purpose of regional detection is achieved.

The invention discloses a uranium layer thickness uniformity measuring and calculating method, which relates to the technical field of nuclear physical detection, and comprises the following steps: measuring the whole uranium layer on the surface of an electrode, firstly measuring the alpha particle emissivity of the whole surface of the electrode and a measured unit through a semiconductor detector, and then calculating to obtain the thickness uniformity of the uranium layer on the surface of the electrode. In the whole testing process, the semiconductor detector does not make contact with the electrodes, the uranium layer cannot be damaged, the semiconductor detector is high in precision and accurate in measurement result, and the uranium layer thickness uniformity can be reflected by the calculation result of the uranium layer thickness uniformity deviation coefficient. The invention further provides a uranium layer thickness uniformity measuring device which is applied to the uranium layer thickness uniformity measuring and calculating method, the alpha particles released by the uranium layer can be measured under the non-contact condition, the emissivity of the alpha particles is directly obtained, and data are provided for the uranium layer thickness uniformity deviation coefficient.

A method of detecting alpha particles may include providing a layer of a scintillating slurry comprising a granular scintillating material in water onto a measurement surface of a sample; positioning the sample having the scintillating slurry within a detection chamber of detection apparatus; detecting photons produced by the granular scintillating material in the scintillating slurry when the granular scintillating material is excited by ionizing alpha radiation emitted by alpha particles within the sample using a photon detector and generating a corresponding output signal; and removing the sample and the scintillating slurry from the detection chamber.

The invention relates to the technical field of positron annihilation lifetime measurement, and provides a positron annihilation lifetime spectrum measurement device, which comprises an alpha particle generation device, an alpha particle detection device, a gamma ray detection device and a lifetime measurement device, and is characterized in that the alpha particle generation device generates alpha particles and first gamma rays through nuclear reaction; the first gamma ray enters a to-be-detected sample, and positron annihilation occurs in the to-be-detected sample to emit a second gamma ray; the alpha particle detection device is used for detecting alpha particles and generating an initial signal; the gamma ray detection device is used for detecting a second gamma ray and generating a termination signal; the lifetime measuring device is used for acquiring a time interval between the start signal and the termination signal to generate a positron annihilation lifetime spectrum. As alpha particles are easy to shield and the detection efficiency is higher than that of gamma rays, the alpha particles are used as initial signals, so that the screening efficiency of effective events and the overall counting rate of the system can be greatly improved, and the positron annihilation lifetime spectrum has good signal-to-noise ratio and measurement accuracy.

The invention discloses a tritium monitor for realizing alpha, beta and gamma background deduction and a tritium activity concentration detection method.The tritium monitor comprises a detector I, a detector II and a signal processing unit, and the detector I is used for detecting alpha particles, beta particles and gamma particles; wherein the beta particles comprise tritium decay beta particles and high-energy beta particles with energy higher than that of the tritium decay beta particles, and the detector II is used for detecting alpha particles, gamma particles and high-energy beta particles and outputting signals II corresponding to counting rates of the particles. The signal processing unit is electrically connected with the detector I and the detector II, and the signal processing unit is configured to be used for receiving the signal I and the signal II, calculating a background equivalent current jointly generated by the alpha particles, the gamma particles and the high-energy beta particles based on the signal II and a preset calibration coefficient, and calculating the total ionization current based on the difference value of the total ionization current and the background equivalent current. And obtaining a net tritium current, and determining the tritium activity concentration based on the net tritium current.

The application discloses a kind of real-time alpha particle detector optimization design method based on air scintillation, with the lowest detection sensitivity as design goal, through Monte Carlo analysis method, carry out multi-parameter optimization design, specifically through detector modeling, threshold and coincidence logic setting, the detection efficiency calculation of alpha particle, cosmic-ray background and the accidental coincidence count rate calculation of PMT and measurement time setting etc. Steps optimize the system parameters of detector, according to the lowest detection sensitivity lower limit principle, determine optimal detector model, threshold and coincidence logic and measurement time etc. The method is simple and easy to understand, high universality, can solve the problem of low detection efficiency of alpha particle and low signal-to-noise ratio of real-time alpha particle detector based on air scintillation due to low air light yield, reach the lowest detection sensitivity lower limit of alpha particle allowed in actual situation, applicable to the efficient real-time measurement of alpha particle concentration / activity under the condition of low radioactivity level with air scintillation.

The present invention discloses a method for obtaining the energy spectrum and angular distribution of a deuterium-tritium neutron source. The method adopts a D-T neutron radiation field measurement system based on a SiC detector, can simultaneously measure the companion particles of the two reactions, can distinguish them in the energy spectrum, and obtain the counting rates of alpha particles and protons; takes into account the influence of the D-D reaction caused by target deposition in the D-T reaction, obtains the energy spectrum and angular distribution of the D-T and D-D neutron sources, and effectively improves the accuracy of the energy spectrum and angular distribution; the method of the present invention has no requirements for target tube-related parameters such as a pipeline and a grating for the companion particles, is simple to operate, only needs to measure a set of data to obtain the energy spectrum distribution in the entire space, does not need to measure different angles one by one, and can measure all D-T neutron sources; and the method of the present invention can be applied to a DC beam or pulsed beam D-T accelerator neutron source with a reserved companion particle channel, especially when there is deuterium beam deposition on the target, and can more accurately obtain the energy spectrum and angular distribution of the D-T neutron source.

The neutron beam detection device of the present application is provided with: a first solar cell type detector, which has a conversion film attached to its surface that converts neutrons into any one of a charged particle beam of a photon, an alpha particle, a proton, a lithium nucleus, a gamma ray, and a beta ray, and generates a current by incident radiation; a radiation detector that generates a current having no sensitivity to neutrons as an output signal due to radiation incident; a current measurer that detects the current generated by the first solar cell type detector and the current generated by the radiation detector due to radiation incident as signals; and a flux calculation section that compares the current signals from the detector detected by the current measurer. The flux calculation section corresponds the detected current signals from the solar cell type detector and the radiation detector to a relationship between the flux of a prescribed kind of incident radiation and the detected current from the solar cell type detector and the radiation detector, which is obtained in advance, and calculates the flux of the neutron beam.

The application relates to an alpha particle measuring device, method, apparatus, storage medium and program product. The device comprises a cavity surrounded by a side wall, a cavity top and a cavity bottom; a collector and a cathode are arranged in the cavity; the collector is arranged on the cavity top and the cathode is arranged on the cavity bottom; the collector is parallel to the cathode; the distance between the collector and the cathode satisfies a first preset distance; the collector comprises a plurality of first anode filaments arranged in a first direction and a plurality of second anode filaments arranged in a second direction; the distance between each first anode filament and each second anode filament in a third direction is a second preset distance; the distance between two adjacent first anode filaments in the first direction is a third preset distance; and the distance between two adjacent second anode filaments in the second direction is a fourth preset distance. The method can improve the accuracy of alpha particle measurement results.

The application discloses a method for measuring surface contamination of long-distance alpha radioactive material, which comprises the steps of measuring long-distance alpha radioactive point source and measuring long-distance alpha surface contamination count rate. The measurement of long-distance alpha radioactive point source comprises intrinsic detection efficiency of alpha particles, collection efficiency calculation and detection efficiency calculation; the measurement of long-distance alpha surface contamination count rate comprises establishing a contamination count rate model, calculating the mean value of point source detection efficiency in each place in a detection area, calculating the expression of the radius R of the detection area D and performing a least square fitting process on the change relation of the radioactive surface source detection efficiency with the opening angle of a shielding body. The application detects fluorescent photons by using a single photon counter, and converts the measured count rate value into the count rate of surface contamination required in the operation intervention level by using the established model.

The application discloses a preparation method of SnBi / B4C radiation shielding composite material. The material selects SnBi alloy with high atomic number, large density, strong processability and corrosion resistance as a matrix, B4C particles with light weight, high strength, good stability and large neutron reaction cross section as reinforcing fillers, and is formed through a powder metallurgy process, so that the composite material with high strength and the ability of shielding thermal neutrons, gamma rays, X rays and alpha particles is obtained. Compared with traditional lead gamma ray shielding materials with single function, the SnBi / B4C radiation shielding composite material solves the problem that neutrons cannot be shielded, and the selected raw materials are non-toxic, so that the composite material is expected to replace lead and be used for radiation shielding in the medical field.

A system includes one or more neutron sources configured to emit neutrons. The system also includes one or more electron detectors configured to detect electrons. Further, the system includes a control system comprising one or more processors. The control system is configured to determine a lithium concentration based on the electrons. Further, the control system is configured to generate a lithium extraction output based on the lithium concentration.

A device for determining radon concentration is provided. The device includes a diffusion chamber, that includes a number of openings that allow radon gas to enter and exit, and a radon sensing arrangement. The radon sensing arrangement includes at least one processing device and one or more detectors, arranged inside the diffusion chamber in such a way that no part of the diffusion chamber is located at a distance, perpendicular to the detector, of more than 20 mm from the closest part of a detector. The at least one processing device is arranged to determine the radon concentration by analyzing and processing the energy spectrum of alpha particles detected by the one or more detectors.

Planar and non-planar microchannel plates (MCPs) made from patterned, channel-forming laminae are provided. Also provided are methods of fabricating the MCPs by assembling patterned, dielectric laminae into slabs and methods of using the MCPs to detect photons, including gamma rays, neutrons, charged particles, such as electrons and ions, alpha particles, tritons, and fission products. In the methods of fabricating the MCPs, a slab is assembled via the side-by-side stacking of laminae into a slab. Prior to being incorporated into the slab, the surfaces of the laminae are patterned such that they define structured channels for electron multiplication extending through the thickness of the slab. The channels can run parallel or non-parallel, can have uniform or non-uniform shapes and dimensions, and can have interior surfaces with uniform or non-uniform chemical compositions or surface textures.

The online alpha combination detector of the application integrates ZnS(Ag) detector and PIPS (ion implantation type passivated silicon) detector; ZnS(Ag) and PIPS are not sensitive to environmental gamma rays, so that the device of the application has a lower background and a lower detection limit without additional shielding device; ZnS(Ag) is also not sensitive to beta rays, and the interference of beta rays on ZnS(Ag) can be ignored by reasonably setting the threshold value; for PIPS, the energy spectrum of beta rays is concentrated in the low energy region, and the interference of beta rays can also be excluded by energy spectrum analysis algorithm or improving the lower limit of the energy spectrum threshold; in this way, the influence of beta and gamma rays on the combination detector for measuring alpha particles is greatly reduced, and the detection accuracy of alpha particles is improved; the ZnS(Ag) detector is coupled with multiple PMTs, which further ensures the detection efficiency; the detection window structure benefits from the unique design and is easy to replace; the window materials such as aluminum foil, titanium foil and gold foil are flexibly adapted; the detector is resistant to strong acid and strong alkali and corrosion, and has a wider use scenario.

A neutron measurement system and method based on a nano-coated pixel sensor, relating to the field of neutron measurement technology. The neutron measurement system based on a nano-coated pixel sensor includes a detector; the detector includes an active pixel sensor; the photosensitive surface of the active pixel sensor is not encapsulated in glass, and the photosensitive surface of the active pixel sensor has a layered neutron conversion material. A neutron measurement method is applied to the neutron measurement system based on a nano-coated pixel sensor; the method is as follows: a neutron undergoes a nuclear reaction with a target element, and the generated alpha rays are incident on the photosensitive surface of the active pixel sensor, causing the active pixel sensor to generate a radiation response signal; the indirect measurement of neutrons is achieved by statistically analyzing the radiation response signal. The advantage of this invention is that by combining a specific neutron conversion material with an active pixel sensor, neutron detection is transformed into alpha particle detection, which is the strength of the active pixel sensor, significantly improving the detection efficiency of neutrons (especially thermal neutrons).

An implantable marker is configured to deliver a therapy to a patient and includes a marker and a target isotope. The marker is configured to enhance visibility of a treatment region of the patient when implanted in the patient and viewed with an imaging modality. The target isotope is coupled to at least a portion of the marker, and has a non-radioactive state and a radioactive state. At least a portion of the target isotope is configured to be induced from the non-radioactive state to the radioactive state when the target isotope is irradiated with one or more of gamma rays, neutrons, alpha particles, beta particles, or ions. The target isotope emits a localized therapeutic dose of radiation to target tissue adjacent the implantable marker when the target isotope is in the radioactive state.

The present invention relates to an alpha spectrometry scanner for measuring one or more characteristics of radiation particles received from a radioactive sample under test, which sample is comprised in a radiopharmaceutical, said scanner comprising: detector means comprising a pixelated detector comprising a two dimensional array of detector pixels sensitive to said radiation particles received from said sample; a readout circuit in electric communication with said detector means, arranged to readout each pixel of said array, and wherein said readout circuit is arranged to generate, based on said readout of each of said detector pixels, a charge pattern for each hit of a radiation particle on said detector means, said charge pattern comprising spatial data, temporal data and energy deposited for each detector pixel of said array; spectroscopic analyser means in electric communication with said readout circuit to receive each charge pattern generated by said readout circuit, wherein said spectroscopic analyser means are arranged with a selective algorithm to extract features from said charge pattern and to identify and quantify a corresponding alpha particle of said sample based on said extracted features; a collimator arranged for selecting radiation particles that are on a path from said radioactive sample under test, towards said detector means, wherein said collimator is positioned in front of said detector means, and is comprised of an alpha particle vacuum collimator or an alpha particle air-flush collimator, said vacuum collimator or air-flush collimator is arranged to restrict the passage of said radiation particles and select particles on the path towards the pixels of the array of the pixelated detector.

The invention provides an intrinsic measurement method and device for thorium. The intrinsic measurement method comprises the following steps: recording detection time of alpha particles released by decay of to-be-measured < 220 > Rn gas and daughter < 216 > Po in a measurement chamber; performing Bayesian analysis according to the detection time, and calculating a 220Rn-216Po true coincidence count; and according to the < 220 > Rn count, the < 216 > Po count and the < 20 > Rn-< 216 > Po true coincidence count, calculating the activity concentration of the thorium. According to the intrinsic measurement method and device, two alpha particles emitted by successive decay of 220Rn and 216Po are utilized to form an intrinsic characteristic conforming to a signal, so that the detection efficiency is reduced; the detection efficiency is reduced, so that the method and the device do not need to measure the detection efficiency of the standard scale from the outside, and have self-traceability; meanwhile, the influence of the change of the detection efficiency on the measurement accuracy is avoided, and the measurement accuracy is improved.

The invention relates to a DT labeled neutron source transmission CT imaging detection system and method.The DT labeled neutron source transmission CT imaging detection system comprises a neutron source device, a sample table, a ray detector and a data acquisition and analysis system.The neutron source device is a DT neutron source, and the ray detector comprises a neutron detector array and an associated alpha array detector; the neutron detector array and the associated alpha array detector are respectively arranged in two opposite directions of the neutron source device, the sample table is arranged between the neutron source device and the neutron detector array, and the neutron detector array and the associated alpha array detector are respectively connected with the data acquisition and analysis system. According to the method, the transmission neutron counting rate of each neutron detector unit is obtained by using a flight time method according to time-space correlation characteristics of neutrons and alpha, a high-signal-to-noise-ratio transmission neutron image is obtained by using a tomography mode, and a three-dimensional image structure of a detected sample is obtained by using a filtered back projection algorithm.