10 results about "High atomic number" patented technology

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 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 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.

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.

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.

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.

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.