25 results about "High atomic number" patented technology

The invention provides anti-ionizing radiation powder with a core-shell heterogeneous gradient structure and a preparation method and application of the anti-ionizing radiation powder, and belongs to the field of radiation protection.The preparation method of the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure comprises the following steps that high-atomic-number metal salt is added into deionized water, aging, washing, drying and primary calcination are conducted in sequence, and the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure is obtained; a core layer is obtained; the core layer and low-atomic-number metal salt are added into deionized water, aging, washing, drying and primary calcination are sequentially conducted, and preliminary wrapping powder with the high-atomic-number metal core layer wrapped by low-atomic-number metal is obtained; and adding the preliminarily wrapped powder and rare earth salt into deionized water, and sequentially performing aging, washing, drying, primary calcining, secondary calcining, airflow crushing and air rotation purging to obtain the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure. Through cooperation of the core-shell heterostructure, the high-atomic-number oxide, the low-atomic-number oxide and the multi-element rare earth element, the shielding performance of the material is remarkably improved.

The invention discloses a rare earth based halide scintillator and a preparation method and application thereof, and belongs to the technical field of functional materials. The chemical formula of the rare earth based halide scintillator provided by the invention is RE (DMSO) 8 [Bi < 1-x > Sb < x > Cl6], wherein 0 < x < = 1; rE is a rare earth element; dMSO is a dimethyl sulfoxide ligand. By introducing the DMSO ligand and combining antimony doping, the formed rare earth based halide scintillator has intrinsic high atomic number, no self-absorption rare earth emission, no toxic element and outstanding comprehensive optical performance, so that the antimony-doped rare earth based halide scintillator has good luminescence performance and can be applied to the field of luminescent devices. Particularly, the compound has good fluorescence quantum efficiency and light yield, and has a good application prospect in the fields of detection, imaging or luminescence.

The application provides a core-shell heterogeneous gradient structure anti-ionizing radiation powder and a preparation method and application thereof, and belongs to the field of radiation protection. The preparation method of the core-shell heterogeneous gradient structure anti-ionizing radiation powder comprises the following steps: adding a high-atomic-number metal salt into deionized water, sequentially performing aging, washing, drying and primary calcination to obtain a core layer; adding the core layer and a low-atomic-number metal salt into deionized water, sequentially performing aging, washing, drying and primary calcination to obtain a preliminary wrapped powder in which a low-atomic-number metal wraps a high-atomic-number metal core layer; adding the preliminary wrapped powder and a rare earth salt into deionized water, sequentially performing aging, washing, drying, primary calcination, secondary calcination, airflow pulverization and air rotation blowing to obtain the core-shell heterogeneous gradient structure anti-ionizing radiation powder. Through the synergy of the core-shell heterogeneous structure, high-atomic-number and low-atomic-number oxides and multiple rare earth elements, the shielding performance of the material is significantly improved.

The invention provides an X-ray composite radiation shielding material and a preparation method and application thereof, and belongs to the technical field of radiation protection. The photoelectric effect and the scattering effect of X-rays in the material are remarkably enhanced by using high atomic number elements contained in the metal oxide, so that the transmittance of the X-rays is effectively reduced. Meanwhile, the oxide material has good chemical stability and environmental friendliness, and the toxicity and aging problems caused by a traditional lead-based shielding material can be avoided. The prepared composite radiation shielding material has the advantages of being low in cost, light in weight, easy to process, good in flexibility, non-toxic, environmentally friendly and the like, the shielding efficiency of an X-ray shielding coating reaches up to 70% or above when the X-ray photon energy is 70 kV or below, and the generated secondary reflectance can be reduced by 35-80% compared with lead.

The invention relates to the technical field of neutron radiation measurement, discloses a neutron nondestructive testing wide-spectrum moderation device for a laser neutron source and a detection method, and adopts a three-in-one design idea of material function compounding, space structure nesting and energy step matching. An integrated structure formed by concentrically nesting an inner layer, a middle layer and an outer layer in sequence from inside to outside is adopted; the inner layer adopts a high-Z inelastic moderator, the middle layer adopts a low-absorption elastic moderator layer, and the outer layer adopts a thermalization and mechanical constraint shell; through physical combination and space structure optimization of a high atomic number material and a low atomic number material, step-by-step, collaborative and stepped efficient moderation of the neutron spectrum in the laser white light is realized. An integrated moderation structure formed by sequentially and concentrically nesting a high atomic number inelastic moderation layer, a low-absorption elastic moderation layer and a thermalization restraint layer from inside to outside is adopted, and step-by-step, collaborative and stepped efficient moderation and regulation and control of the wide energy spectrum of the laser white light neutron source are achieved.

The utility model discloses a double-X-ray energy spectrum acquisition device and online detection equipment. The double-X-ray energy spectrum acquisition device comprises a first energy spectrum acquisition module and a second energy spectrum acquisition module, the first energy spectrum acquisition module comprises a low-atomic-number target X-ray emitter and a first energy spectrum detector, first X-rays emitted by the low-atomic-number target X-ray emitter irradiate a to-be-detected sample to generate first characteristic X-rays, and the first characteristic X-rays are received by the first energy spectrum detector to obtain a first energy spectrum signal; the second energy spectrum acquisition module comprises a high atomic number target X-ray emitter and a second energy spectrum detector, a second X-ray emitted by the high atomic number target X-ray emitter irradiates the sample to be detected to generate a second characteristic X-ray, and the second characteristic X-ray is received by the second energy spectrum detector to obtain a second energy spectrum signal. According to the scheme, the problem that the detection precision of online detection equipment is poor can be solved.

The invention discloses a compact high-resolution epithermal neutron resonance absorption spectrum method and a compact high-resolution epithermal neutron resonance absorption spectrum device in the technical field of nuclear physics application, and aims to solve the problems of large size, high cost and limited application of a traditional epithermal neutron source. The method comprises the following steps: generating an epithermal neutron source with high repetition frequency and microsecond-level pulse by using a kilohertz femtosecond laser, accelerating an electron beam through a laser plasma wake field, bombarding a metal target to generate fast neutrons, and processing the fast neutrons through a polyethylene body to obtain an epithermal neutron energy spectrum with ultrahigh energy resolution; the device comprises a femtosecond laser, a vacuum target chamber, a supersonic nozzle, a high-atomic-number metal target, polyethylene, a collimator, an EJ-420 detector and other key components, and is compact in design, convenient to move and convenient for multi-scene application. The technology can realize accurate diagnosis of the type and abundance of nuclides in nuclear fuel and nuclear waste and non-contact temperature measurement in a special environment, and has important nuclear safety and nuclear guarantee application values.

The invention discloses a method for preparing high-entropy gamma-ray shielding filler based on a multilayer electrophoresis method, and belongs to the technical field of shielding materials. The invention aims to solve the problems of low shielding efficiency and complex process caused by non-uniform component distribution and weak interface bonding force of the traditional shielding filler. The method comprises the following steps: dispersing a plurality of high-atomic-number metal salts in deionized water, immersing a conductive base material into a polyelectrolyte solution for surface modification, performing electrophoretic deposition under the conditions of regulating and controlling voltage, pH and deposition time to realize gradient deposition of metal ions on the surface of the base material, drying, sintering, and grinding to obtain the compact high-entropy gamma-ray shielding filler. The method has the advantages that atomic-scale mixing can be achieved through the multi-layer electrophoresis method, and the segregation problem of traditional mechanical mixing is avoided; the multi-layer design enhances multiple scattering and absorption of gamma rays, so that the effect of improving the shielding efficiency is achieved; the process is simplified, high-temperature smelting or complex pressing equipment is not needed, and energy consumption and cost are reduced.

We have developed a new type of target for linear particle accelerators, capable of converting electrons into X-rays with an efficiency comparable to that of conventional targets (such as bulk tungsten), and a greater resistance to high irradiation (reduced risk of target melting). Our target prototype consists of several layers of a substrate material (combining good thermal conductivity, low atomic number of its constituents, and high melting temperature), in which are implanted pads made of elements with high Bremsstrahlung conversion power (i.e., elements with high atomic number). We have presented the advantages and limitations of the different types of substrates and pads (ceramic or metallic), and modeled, via a Monte-Carlo approach, the photon spectra obtained with the prototypes with Cu, SiC and diamond substrates, and with W and TaC pads.

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.

The utility model discloses a radiation shielding device for isotope application, which is characterized by comprising a first atomic number material layer, a second atomic number material layer and a third atomic number material layer which are sequentially arranged along a ray output direction, the atomic number of the first atomic number material layer < the atomic number of the second atomic number material layer < the atomic number of the third atomic number material layer. According to the utility model, low-atomic-number to high-atomic-number materials are sequentially adopted according to the output direction of rays, so that the beta radiation protection effect is better, the protection use of the nuclear medicine application is met, and the application is environment-friendly and harmless.

The application discloses a kind of hardening artifact correction method, system, equipment and medium of image, which comprises: obtaining the energy spectrum projection data to be corrected, according to the energy spectrum projection original data obtained by the standard water model of scanning eccentricity, the effective energy spectrum value of the detector channel of energy spectrum CT system in different energy interval is determined;According to the energy spectrum projection data to be corrected and effective energy spectrum value, the correction compensation amount is calculated;The energy spectrum projection data to be corrected is corrected based on the correction compensation amount.The application effectively removes the hardening artifact phenomenon caused by the existence of high atomic number material in the scanned object when the CT device scans the object;Avoid the problem of large amount of calculation and low accuracy caused by image segmentation and forward and backward projection involved in high-order hardening artifact correction method;Reduce the calculation amount of hardening artifact correction, improve the accuracy of hardening artifact correction.

The invention provides a Bi-based material for X-ray detection and protection and a preparation method and application thereof, and belongs to the technical field of X-ray detection and protection. According to the invention, the Bi-based material is BiO (IO3), BiVO4 or Bi2WO6; the preparation method comprises the following steps: mixing an I2O5 solution and a BiH10N3O14 suspension, and reacting to obtain BiO (IO3); the preparation method comprises the following steps: mixing Bi (NO3) 3.5 H2O, NH4VO3 and a nitric acid solution, and dropwise adding ammonia water into the mixed solution until yellow precipitate appears, so as to obtain BiVO4; the preparation method comprises the following steps: mixing a Na2WO4. 2H2O solution and a Bi (NO3). 5H2O suspension, and reacting to obtain Bi2WO6. The Bi-based material disclosed by the invention has excellent X-ray detection performance and protection effect, and due to the extremely high atomic number of the Bi element, the high equivalent atomic number and density of the material are finally formed, so that full absorption of X-rays is realized.

A method for obtaining electron microbunches by laser ionization injection, which is based on a laser wakefield acceleration system. The method includes the following steps: (1) providing a laser pulse; (2) allowing the laser pulse to enter an injection stage, where the injection stage uses a mixed gas plasma of a high atomic number gas and a low atomic number gas; the laser pulse interacts with the mixed gas to form electron microbunches; (3) ionizing the inner-layer electrons of high atomic number atoms near the peak intensity of the laser pulse; (4) the electrons with an initial spatial distribution released by ionization slide towards the tail of the plasma bubble; (5) allowing the laser pulse and the electron microbunches to enter an acceleration stage, where the acceleration stage uses a low atomic number gas, and the electron microbunches are continuously bunched and accelerated. The present invention obtains electron microbunches by laser ionization injection, greatly reducing the experimental conditions and saving costs.

The invention relates to the technical field of CT image reconstruction, and discloses a cone beam CT scanning image rapid reconstruction system and method based on deep learning, and the system comprises a dual-ray generation module, a scanning module, a deep learning reconstruction module, and a result output module. The dual-ray generation module comprises two ray generators, a beam outlet of one ray generator is provided with a 0.1 mm low atomic number material aluminum to filter an X-ray ultra-low energy part, and the other beam outlet is provided with a 0.1 mm high atomic number material copper to attenuate the X-ray low energy part. According to the method, the dual-energy-spectrum projection data is obtained through the dual-ray generator, the tissue linear attenuation coefficient is solved through fitting by taking PMMA and aluminum as base materials, background interference is corrected in combination with air reference data, the error of the reconstructed CT value in the soft tissue area is smaller than or equal to + / -10 HU, the error of the reconstructed CT value in the cortical bone area is smaller than or equal to + / -30 HU, and compared with traditional CBCT, the method is more accurate, and a reliable foundation is laid for preventing power ratio calculation.

An absorber for electromagnetic calorimeters that comprises a front portion and a rear portion that are made of different materials. The front portion may comprise a first material that is resistant to blow off (which can result in spalling) and vaporization from electromagnetic radiation (e.g., X-rays) exposure. The rear portion may comprise a second material that has a higher atomic number than the first material. For example, the example, the front portion may comprise graphite and the rear portion may comprise aluminum. The front portion may comprise 1 millimeter (mm) (0.039 inches (in)) thick AXM-5Q graphite, and the rear portion may comprise 1 mm (0.039 in) thick 6061-T6 aluminum. Thus, the absorber may fit into existing calorimeter housings and absorb high energy electromagnetic radiation at a sufficient rate, without undesirable levels of blow off or vaporization.

Described is a measuring structure (100) for PET or SPECT applications comprising a matrix of scintillation crystals (200) configured for simultaneously measuring radiation directed along respective directions. each crystal (200) extending along a longitudinal axis (X) between an upper surface (200a) and a base surface (200b) opposite the upper surface (200a), each scintillation crystal (200) having, along the longitudinal axis (X), a variable transversal section. The structure also comprises a grille (300) defining a plurality of through seats each configured for receiving a respective scintillation crystal (200). Each seat has inner walls (301) shaped to match a lateral surface of the respective scintillation crystal (200). The grille (300) is made of a metal material with a high atomic number designed to screen incident radiation.

A converter for converting an electron beam into photons is provided. The converter can include a plurality of spherical beads made of high atomic number (high-Z material) disposed within a coolant fluid. The converter can include an inlet and an outlet for the coolant fluid. The coolant fluid can flow in a opposite direction as a direction of an electron beam.

The invention belongs to the field of radiation detection and X-ray imaging, and discloses Yb < 3 + > doped oxyfluoride scintillation glass capable of avoiding visible light crosstalk, an optical fiber and a preparation method and application of the Yb < 3 + > doped oxyfluoride scintillation glass. The scintillation glass is prepared from the following raw materials in percentage by mole: 5 to 30 percent of high atomic number element compound, 0.01 to 10 percent of alkali metal compound, 45 to 70 percent of silicon dioxide, 5 to 25 percent of aluminum compound and 0.01 to 2 percent of externally doped Yb < 3 + > source, wherein the sum of the components is 100 percent. The Yb < 3 + > doped oxyfluoride glass and the optical fiber thereof have excellent optical performance and environmental stability, and X-ray imaging capable of avoiding visible light crosstalk can be realized by combining the Yb < 3 + > doped oxyfluoride glass with a 900nm long-pass filter. In addition, the Yb < 3 + >-doped infrared band scintillation optical fiber has lower transmission loss compared with a visible band emission scintillation optical fiber, and can be used in the related fields of environmental monitoring, X-ray imaging, industrial detection and the like.

The invention discloses a fusion radiation imaging diagnostic device based on a lead tungstate array. Comprising a radiation collimator, a scintillator array, a photoelectric converter, a data acquisition unit, an imaging system and a shielding assembly. The radiation collimator is made into a porous grid structure by adopting a high-density heavy metal thick target and is locked at a diagnosis window at the lower part of the fusion device; the scintillator array is a pixelated array formed by a plurality of lead tungstate scintillator units, is arranged in one-to-one correspondence with the collimation micropores, and converts incident high-energy radiation into scintillation light signals; the photoelectric converter is in pixel coupling with the scintillator array pixel pair and converts an optical signal into an electric signal; the data acquisition unit acquires and preprocesses the electric signals and then transmits the electric signals to the imaging system to realize two-dimensional or three-dimensional imaging of radiation distribution. The high density, high atomic number and excellent radiation resistance of lead tungstate are utilized, and a high length-diameter ratio collimation structure is combined, so that the problems of insufficient radiation resistance and lack of spatial resolution capability in a high-flux neutron-gamma mixed radiation environment are solved.

The invention discloses a high-entropy alloy composite coating with matched high and low atomic numbers and a preparation method of the high-entropy alloy composite coating, and belongs to the technical field of functional materials and preparation of the functional materials. The problem that an existing high-entropy alloy composite coating has a weak radiation depletion region is solved. Light atoms with small atomic sizes are doped in metal gaps in a gap filling mode through cooperation of high atomic numbers and low atomic numbers, electrons are effectively prevented from directly penetrating through energy loss gaps in the gaps, and therefore the shielding performance of the light atoms on high-energy electrons is improved; and the influence of a radiation depletion weak region of the existing high-entropy alloy on the radiation shielding efficiency is made up. The doping of the light atoms can influence the state of electrons around the metal, so that the electrons can form a denser electron region around the light atoms, the collision probability of the electrons in unit cells is increased, the maximization of non-elastic collision of extranuclear electrons is realized, and the protection performance of the composite material on the electrons is further improved; therefore, the tolerance of the device in high-energy electrons is improved.

This invention belongs to the field of optical thin film technology, specifically relating to a reflector, its fabrication method, and its application. The invention provides a reflector comprising a substrate and a plurality of reflective film units and a tungsten layer sequentially stacked on the surface of the substrate. Each reflective film unit comprises, from bottom to top, a single-element silicon layer, a high atomic number metal layer, and a silicon carbide layer sequentially stacked. The silicon carbide layer and the tungsten layer of the reflective film unit are in contact. The high atomic number metal layer is made of Rh, Au, or Pt. By adding a high atomic number metal layer to the SiC / Si composite film system, this invention can further improve the energy bandwidth of the composite film. At near-normal incidence angles, the reflector obtained by this invention maintains a relatively high reflectivity in the energy range of 40 eV to 80 eV, forming a high-reflectivity plateau region, greatly expanding the applicability of the reflector.

The present invention relates to a nanoparticle comprising a high atomic number element for use in a method of treating a tumor by radiopharmaceutical therapy in a subject in need thereof; the method comprises the step of jointly administering an effective amount of the nanoparticles containing the high atomic number elements and an effective amount of the therapeutic radiopharmaceutical containing the radionuclide, wherein the effective amount of the nanoparticles containing the high atomic number elements and the effective amount of the therapeutic radiopharmaceutical containing the radionuclide are combined; wherein the nanoparticles containing high atomic number elements comprise elements with atomic numbers greater than 40, preferably greater than 50; and wherein the nanoparticles have an average hydrodynamic diameter of 20 nm or less, for example between 1 nm and 10 nm, preferably between 2 nm and 8 nm.

Described is a measuring structure (100) for PET or SPECT applications comprising a matrix of scintillation crystals (200) each having a bar shape and extending along a longitudinal axis (X). Wherein the scintillation crystals (200) are parallel to each other and oriented in such a way as to define a measuring direction (R) that is transversal to the longitudinal axis (X). The measuring structure (100) comprises a first electronic conversion circuitry associated with the first surface (200a) of each scintillation crystal (200) for receiving an optical signal and converting it into an electric signal and a second electronic conversion circuitry associated with the second surface (200b) of each scintillation crystal (200) for receiving an optical signal and converting it into an electric signal. The scintillation crystals (200) are separated from each other by at least first sheets (300a) perpendicular to the measuring direction (R) and made of a metal material with a high atomic number designed to screen the incident radiations having energy that is lower than a predetermined threshold.

The present application belongs to the technical field of nuclear radiation detection and imaging, and particularly relates to a 3D coded gamma imaging detector based on a magic cube structure and an imaging method thereof. The gamma imaging detector adopts a spatial geometric array layout; in a plurality of spatial cells of the array, shielding units and detection modules are randomly filled heterogeneously. The shielding units adopt high-atomic-number materials, and are used for spatial modulation of omnidirectional incident gamma rays, to form anisotropic response characteristics. The detection modules are used for recording energy deposition and counting information of the gamma rays. The present application expands the traditional 2D planar coded gamma imaging into a 3D magic cube structure gamma imaging with three-dimensional spatial topology coding, and constructs a three-dimensional omnidirectional system response array by using the random distribution of the shielding units and the detection blocks in space. Without a complex coincidence electronics data acquisition system, the spatial correlation of the counts of each unit is solved, to realize accurate reconstruction of the spatial position and intensity distribution of a high-energy gamma ray source.