14 results about "Radioactive Disintegrations" patented technology

The invention provides an off-site full-range radiation risk evaluation method and system under a severe accident of a nuclear power plant, and the method comprises the steps: S1, building a radioactive accident risk evaluation basic model architecture, adapting to a model demand, and building a corresponding basic database; s2, constructing radioactive smoke plume characteristics after the accident; s3, calculating accident site space gridding and smoke plume transmission discretization; s4, sampling meteorological conditions, and simulating smoke plume transmission; s5, calculating the radiation dose in the early stage of the grid domain, and carrying out risk assessment; s6, performing risk assessment on the health effect in the early stage of the grid domain; s7, calculating the medium-and-long-term stage radiation dose in the grid domain, and performing dose risk assessment; and S8, performing health effect risk assessment and accident consequence assessment in the medium-and-long-term stage. According to the method, the whole transportation process of the radioactive smoke plume under a serious accident is simulated, loss effects such as dry and wet settlement and radioactive decay of the smoke plume are considered, and the activity of the radionuclide deposited on the ground and retained in the air in the off-site space range is determined.

Systems and methods are disclosed for determining the spatial distributions of radionuclides in tissue samples via mass spectrometry imaging. After administration of a radiopharmaceutical that contains a radionuclide, a mass spectrometry imaging system, such as an imaging mass cytometer or a multiplexed ion beam imaging system, is employed to interrogate a tissue sample to obtain a dataset. The radiopharmaceutical includes, or generates via radioactive decay of the radionuclide, a metal isotope detectable by the mass spectrometry imaging system. The dataset is processed to determine a spatial distribution of the metal isotope within the tissue sample, thereby characterizing the spatial distribution of the radionuclide delivered within the tissue sample. The tissue sample may be stained with a biomarker reagent that includes an additional metal isotope attached to a biomarker ligand, enabling the spatially multiplexed and co-registered analysis. The present methods can be adapted to infer and assess localization of non-radioactive pharmaceuticals.

A system and method for simultaneous imaging of multiple positron emission tomography (PET) tracers in which digital data including PET information associated with at least two time points is received, where the digital data is generated by PET scans of a region of interest of a physiologic body which has been administered at least two PET tracers that differ from one another at least in their radioactive decay constant. At least one set of output digital data is determined based on the radioactive decay constants of each PET tracer, the at least one set of output digital data corresponding to at least one of the at least two PET tracers. The determination of at least one set of output digital data includes at least one of regularizing to account for statistical noise, preconditioning the digital data to be more amenable to signal separation, applying feature preservation techniques, or accounting for late tracer kinetics.

The application provides a method and system for evaluating the whole range of radiation risk outside a nuclear power plant in a severe accident, and the method comprises the following steps: S1, a basic model architecture for evaluating the risk of radioactive accidents is built, the model requirements are adapted, and a corresponding basic database is established; S2, the characteristics of the radioactive plume after the accident are constructed; S3, the spatial gridding of the accident site and the discretization of the plume transmission are calculated; S4, the sampling meteorological conditions are obtained, and the plume transmission is simulated; S5, the radiation dose in the early stage of the grid domain is calculated, and the risk is evaluated; S6, the health effects in the early stage of the grid domain are evaluated; S7, the radiation dose in the medium and long term stage of the grid domain is calculated, and the dose risk is evaluated; S8, the health effect risk in the medium and long term stage is evaluated, and the consequences of the accident in the medium and long term stage are evaluated. The application simulates the whole transport process of the radioactive plume in a severe accident, considers the dry and wet deposition of the plume and the loss effects such as radioactive decay, and determines the activity of the radionuclide deposited on the ground and retained in the air within the spatial range outside the scene.

The application provides a method for evaluating radioactivity in a limited space based on a plume diffusion mode, which is mainly used for evaluating radioactivity concentration distribution in the limited space, and the method comprises the following steps: equivalent processing of a radioactivity diffusion process, regarding the radioactivity diffusion process as a plume bundle composed of a plurality of smoke clusters, and obtaining the radioactivity concentration distribution through a Gaussian smoke cluster diffusion model; improving a traditional Gaussian smoke cluster model by considering radioactivity source intensity variation, gravity settlement and environmental wind speed, considering the variation of the radioactivity intensity of the smoke cluster according to radioactivity decay, considering the offset amount of the gravity settlement to the center line of the plume according to Stokes formula, and synthesizing and superimposing diffusion speed according to the parallelogram rule to combine the environmental wind speed and the radioactivity self-diffusion speed; and superimposing the radioactivity concentrations of all the smoke clusters according to the improved smoke cluster model to evaluate the radioactivity concentration in the limited space.

The invention discloses a time-space sequence modularization supergravity test method for simulating a nuclide ten-thousand-year migration process in a geological barrier and application of the time-space sequence modularization supergravity test method. A kilometer-level geological barrier is spatially dispersed into representative space-time sequence geological modules such as a deep part-near part, a middle part, a shallow part-far part and the like along a nuclide migration path so as to realize reconstruction of a ten-thousand-year full-cycle migration process. A differentiated entity fracture model is constructed through 3D printing for different modules, and differentiated stress and hydraulic boundary conditions matched with the geological depth are applied under a high gravity field. The test adopts stable replacement nuclide, and through a concentration correction method based on transmission lag and a radioactive decay law, outlet concentration data of an upper-level module is converted into an inlet concentration boundary of a lower-level module, so that continuous tests of different space-time sequence geological modules are realized. And finally, restoring a time scale and splicing data by using a supergravity physical simulation similarity law, and reconstructing a full-path concentration penetration curve of the nuclide under a ten-thousand-year scale.

The present application relates to the field of radon Rn222 measurement, and particularly to a radon measuring instrument calibration radon Rn222 measuring chamber and a testing method thereof. The radon measuring instrument calibration radon Rn222 measuring chamber comprises a sealed chamber, a radium chloride 226 decay chamber arranged in the sealed measuring chamber and provided with a decay chamber to release radon Rn222 by radioactive decay of radium chloride 226, an air inlet hole and an air outlet hole arranged at two ends of the radium chloride 226 decay chamber respectively, a radon measuring instrument assembly arranged at one end of the radium chloride 226 decay chamber and connected with the air outlet hole, the radon measuring instrument assembly being provided with a plurality of radon measuring instruments to measure radon Rn222 released by radioactive decay of radium chloride 226, and an air inlet assembly. The present application realizes functional integration through modular design, solves the problems of dispersed structure and complex operation of traditional calibration equipment, breaks through the bottleneck of single-channel efficiency through parallel measurement of multiple radon measuring instruments, meets the batch calibration demand, and guarantees stable radon concentration through linkage of the air inlet assembly and the decay chamber, thereby laying a foundation for high-precision calibration.

A low-temperature seed-induced growth method for salicylamide ultrafast scintillation crystals is disclosed, involving ultrafast scintillation crystals and their low-temperature seed-induced growth method. This method aims to solve the technical problems of uncontrollable growth rate, sensitivity to environmental fluctuations, easy generation of microscopic defects within the crystal, and poor dimensional regularity in existing organic crystal scintillators. The method comprises: 1. Obtaining high-quality seed crystals through isothermal volatilization; 2. Preparing a saturated growth solution; 3. Precise temperature equilibration treatment; 4. Seed crystal-induced slow volatilization growth. The salicylamide single crystals prepared by this method reach a size of 15mm × 9mm × 1.5mm. Its photo-induced decay time is approximately 5.93 ns. 137 The radioactive decay time under Cs excitation is approximately 2.82 ns, which can be used in the field of radiation detection.

The invention relates to a process for producing medical-grade lead-212, comprising the steps of: a) production of lead-212 by radioactive decay of radium-224 in at least one first chromatography column containing a first stationary phase on which radium-224 is fixed; b) elution of the lead-212 thus produced from the first stationary phase; c) loading of the eluate thus obtained into a second chromatography column containing a second stationary phase to fix the lead-212 on the second stationary phase; d) washing of the second stationary phase; d) elution of the lead-212 from the second stationary phase; and characterized in that: - step b) comprises circulating in said at least one first chromatography column an ​​aqueous solution A1 comprising from 0.8 mol / L to 1.6 mol / L of a chloride, optionally with at most 200 mmol / L of HCl;and- step d) includes circulating an aqueous solution A2 comprising 0.01 mol / L to 1 mol / L of chloride through the second chromatography column. Applications: manufacture of lead-212 based radiopharmaceuticals, useful in nuclear medicine.

The invention discloses an ecological environment pollution risk assessment method and system, and the method comprises the following steps: collecting radioactivity monitoring data of a target region, and carrying out the preprocessing; constructing a radioactive pollution space-time distribution observation field of the target area, and generating a pollution observation field matrix; coupling the nuclide decay process and the diffusion migration process to form a radioactive decay-diffusion coupling evolution model; constructing a pollution digital twinborn evolution field, and performing simulation calculation on the pollution diffusion state of the target area under the continuous time sequence; constructing a pollution source hypothesis set, and forming a pollution source parameter vector set; iteratively updating and optimizing the pollution source parameter vector set; and calculating a radioactive risk value of each space unit of the target area, performing risk grade division, and generating an ecological environment pollution risk assessment result. According to the method, the radioactive contamination risk assessment is realized by using the decay diffusion coupling and digital twinborn inversion methods, and the method has the advantages of high accuracy and strong space-time description.

The invention relates to a device for radiation detection and analysis, in particular to a portable alpha particle sensor suitable for the identification and quantification of the radioactive decay product-alpha particles-. The proposed invention is a battery-powered pulsed ionization chamber alpha particle sensor comprising at least one battery, at least one switch S, a voltage converter DC / DC, a capacitor C, a processor MCU, a current pulse amplifier A and an ionization chamber K in which a zero potential electrode is placed. The ionization chamber K is designed such that an alpha particle source can be placed therein. Furthermore, at least one battery is electrically connected to the voltage converter DC / DC via a switch S, the operation of which can be controlled by the processor MCU. And the voltage converter DC / DC is electrically connected with the capacitor C and the ionization chamber K. And the electrode of the ionization chamber K is electrically connected with the processor MCU through the current pulse amplifier A. Furthermore, the processor MCU is adapted to execute the following instructions: (i) count the electrical pulses N from the K electrode of the ionization chamber and amplified by the amplifier A; (ii) electrically connecting a supply of electrical energy from the at least one battery to the voltage converter DC / DC and other parts of the circuit in a controllable, periodic manner through the at least one switch S; (iii) determining the value of the voltage across the capacitor C and electrically disconnecting the supply of electrical energy from the battery from the voltage converter DC / DC and other parts in the circuit by the switch S when a previously set maximum value of the voltage is reached.

The invention belongs to the field of isotope geological theory application, and particularly relates to a correction method for the 238U / 235U ratio of a U-Pb isotope system and application of the correction method. The method comprises the steps that 238U and 235U atomic number calculation formulas are arranged according to the radioactive decay law; according to an atomic number calculation formula of 238U and 235U, calculating the initial abundance Ni of parent isotopes 238U and 235U at different moments and the ratio of 238U / 235U, and analyzing the relative deviation of the ratio of 238U / 235U relative to 137.88; a 238U / 235U equation is established for the middle stage of the U-Pb three stages, and evaluation is carried out; and comparing a 238U / 235U calculated value with 207Pb age errors calculated by an original parameter 137.88, and determining qualitative and quantitative use ranges and conditions. According to the method, the reliability of age calculation can be effectively improved, and the method is applied to U-Pb isotope age calculation and isotope evolution research.

The invention relates to the field of radon Rn222 measurement, in particular to a calibration radon Rn222 measurement chamber of a radon detector and a test method of the calibration radon Rn222 measurement chamber. A radon measuring chamber for calibrating and calibrating radon Rn222 of a radon measuring instrument comprises a sealing chamber; the laser chloride 226 decay chamber is arranged in the sealed measurement chamber and is provided with a decay chamber, so that the laser chloride 226 radiates and decays to release radon Rn222, and an air inlet hole and an air outlet hole are formed in the two ends of the laser chloride 226 decay chamber respectively; the radon measuring instrument assembly is arranged at one end of the decay chamber of the radium chloride 226 and is communicated with the air outlet hole, and the radon measuring instrument assembly is provided with a plurality of radon measuring instruments so as to measure radon Rn222 released by radium chloride 226 radiation decay; and an air inlet assembly. Functional integration is achieved through modular design, and the problems that a traditional calibration device is scattered in structure and complex in operation are solved. The parallel measurement design of multiple radon meters breaks through the single-channel efficiency bottleneck and meets the batch calibration requirement; the linkage of the gas inlet assembly and the decay chamber ensures that the radon gas concentration is stable, and a foundation is laid for high-precision calibration.

A system and method for simultaneous imaging of multiple positron emission tomography (PET) tracers in which digital data including PET information associated with at least two time points is received, where the digital data is generated by PET scans of a region of interest of a physiologic body which has been administered at least two PET tracers that differ from one another at least in their radioactive decay constant. At least one set of output digital data is determined based on the radioactive decay constants of each PET tracer, the at least one set of output digital data corresponding to at least one of the at least two PET tracers. The determination of at least one set of output digital data includes at least one of regularizing to account for statistical noise, preconditioning the digital data to be more amenable to signal separation, applying feature preservation techniques, or accounting for late tracer kinetics.