17 results about "Neutron multiplication" patented technology

This invention relates to the field of neutron dose monitoring, specifically to a method and apparatus for monitoring the dose equivalent around neutrons over a wide energy range. The apparatus includes an outer moderator, a thermal neutron absorbing layer, a high-energy neutron compensation layer, and an inner moderator. The high-energy neutron compensation layer is composed of a heavy metal material capable of undergoing a significant neutron multiplication reaction with ultra-high-energy neutrons. The thermal neutron detector is a radiation-resistant solid-state semiconductor detector, comprising a silicon carbide semiconductor substrate and an enrichment layer closely adhering to its surface. 6 The device is equipped with a lithium fluoride thermal neutron converter; an initial thermal neutron detector group is deployed within the device to collect thermal neutron fluence information under different slowing degrees; based on the initial thermal neutron detector group, position optimization and weight coefficient output are performed, and multiple groups of thermal neutron detectors in the first depth order are selected to make the total dose response flat in a wide energy range for dose equivalent monitoring.

A nested pebble bed blanket surrounding a fusion reactor's vacuum chamber includes stacks of nested pebbles composed of neutron multiplier shells filled with breeding spheroids. The shells have perforations passing through their inner and outer surfaces, and they include coolant distributor elements coupled or unitary with the inner surfaces that facilitates the coolant flow into the sphere, sweeping and cooling the inner breeding spheroids and the blanket as a whole. When bombarded by neutrons, the nested pebbles produce a fusion fuel to sustain fusion reactions and are replenished with conveyor systems. A separator extracts the fusion fuel from the blanket coolant, and the reactor's heat from the walls and nested pebble bed is extracted by inert gases and conveyed to a thermal storage and / or a power cycle

This invention discloses a beryllium-titanium alloy microsphere for neutron multiplication materials and its preparation method, belonging to the field of beryllium-titanium alloy technology. The preparation method includes: Step S1, ball milling and mixing beryllium powder and titanium powder at a predetermined mass ratio, followed by a first dry particle composite process to obtain beryllium-titanium spherical powder. Step S2, adding a polyvinyl alcohol binder to the beryllium-titanium spherical powder, followed by a second dry particle composite process to obtain beryllium-titanium granulated powder. Step S3, filling the beryllium-titanium granulated powder into multiple flexible spherical molds, then placing the multiple flexible spherical molds into a sleeve and performing cold isostatic pressing to obtain beryllium-titanium powder blank microspheres. Step S4, degreasing the beryllium-titanium powder blank microspheres under inert gas protection. Step S5, sintering the degreased beryllium-titanium powder blank microspheres to obtain beryllium-titanium alloy microspheres with a diameter of not less than 5 mm and a relative density ≥ 98%.

The invention provides a wide-energy-spectrum neutron dose rate meter, and the meter comprises a mechanical structure assembly which comprises a proportional counter tube, a neutron moderator layer, and a neutron multiplier layer; wherein the neutron moderator layer wraps the proportional counter tube, and the neutron multiplier layer is arranged between the neutron moderator layer and the proportional counter tube; and the circuit board is used for providing working voltage for the proportional counter tube and processing a detection signal output by the proportional counter tube.

The application discloses a porosity calculation method and system for complex reservoirs, which comprises the following steps: selecting a marker layer, and performing preliminary correction on original neutron and density logging curves of a target layer by using deviation analysis according to skeleton neutron values and skeleton density values of the marker layer; based on core analysis test data of the target layer, core data is homed in the preliminary corrected neutron and density logging curves, and a fusion analysis chart is formed based on this; the fusion analysis chart is corrected in neutron values by using a neutron multiplication factor initial value, and a neutron multiplication factor final value is determined by comparing a formation porosity calculation value obtained by using the corrected neutron and density with a formation porosity measurement value; and the original neutron and density logging curves are comprehensively corrected by using the preliminary correction amount and the neutron multiplication factor final value, so that the formation porosity of a single well is obtained.

The invention relates to the field of neutron dose monitoring, in particular to a wide-energy-region neutron surrounding dose equivalent monitoring method and device. The device comprises an outer-layer moderator, a thermal neutron absorption layer, a high-energy neutron compensation layer and an inner-layer moderator, wherein the high-energy neutron compensation layer is made of a heavy metal material which can generate a remarkable neutron multiplication reaction with ultrahigh-energy neutrons; the thermal neutron detector is a radiation-resistant solid-state semiconductor detector and comprises a silicon carbide semiconductor substrate and a < 6 > Li-enriched lithium fluoride thermal neutron converter tightly attached to the surface of the silicon carbide semiconductor substrate; an initial thermal neutron detector group used for collecting thermal neutron fluence information under different moderation degrees is arranged in the device. And based on the initial thermal neutron detector group, performing position optimization and weight coefficient output, and selecting a plurality of groups of thermal neutron detectors in a first depth order, so that the total dose response is flat in a wide energy region and dose equivalent monitoring is performed.

The present invention provides a method, apparatus and equipment for nuclear criticality safety calculation of uranium solution. Among them, the method includes: obtaining material parameters and geometric parameters in the uranium solution system; the uranium solution system is a dissolver containing uranium solution; the uranium enrichment of the uranium solution is less than 20%; constructing a lattice model according to the material parameters, the geometric parameters and nuclear fuel rods; calculating the effective neutron multiplication factor of the uranium solution system through the lattice model. The solution provided by the present invention can improve the accuracy and precision of nuclear criticality safety calculation.

The present invention proposes a three - level coarse - mesh finite - difference acceleration method for domestic DCU architecture, belonging to the cross - technical field of neutron physics and high - performance computing. The method includes: in the three - dimensional characteristic - line transport scanning stage, according to the domain - decomposition method, the computing tasks are sent to the device side (domestic DCU). Inside the DCU, according to the coarse - mesh vertices, edges and faces to which the trajectory segments belong, the neutron flux on the coarse - mesh surfaces to which the trajectory segments belong is stored, and the neutron flux that needs data transfer at the communication - domain boundary is stored; in the three - level coarse - mesh finite - difference method, the calculation results of the characteristic - line three - dimensional characteristic - line transport solution are transferred to the three - level coarse - mesh finite - difference solution module. Among them, the three - level coarse - mesh finite - difference performs multiple coarsening acceleration calculations in terms of energy groups and geometric structures, that is, a coarser mesh with a higher coarsening degree is used to accelerate the iterative calculation of the previous - level coarse mesh. The coarsening degrees of the three - level meshes from small to large are represented as the multi - energy - group cell - level mesh, the single - energy - group cell - level mesh and the single - energy - group assembly - level mesh. Then, the finite - difference equations of each level of the coarse mesh are constructed and solved using the successive over - relaxation iteration method. Finally, the fluxes in each flat - source region are updated according to the calculation results, and the effective neutron multiplication factor in the current iteration is calculated. The present invention relates to the cross - technical field of neutron physics and high - performance computing.

The invention discloses a beryllium-titanium alloy pellet for a neutron multiplication material and a preparation method of the beryllium-titanium alloy pellet, and belongs to the technical field of beryllium-titanium alloys. The preparation method comprises the following steps: S1, carrying out ball-milling mixing on beryllium powder and titanium powder according to a preset mass ratio, and then carrying out first dry particle compounding to obtain beryllium-titanium spherical powder; and S2, after a polyvinyl alcohol binder is added into the beryllium-titanium spherical powder, secondary dry particle compounding is carried out, and beryllium-titanium granulated powder is obtained. And S3, a plurality of flexible spherical molds are filled with the beryllium-titanium granulation powder, then the flexible spherical molds are put into a sheath, and then isostatic cool pressing is carried out, so that beryllium-titanium powder blank pellets are obtained. And S4, the beryllium-titanium powder blank small balls are degreased under inert gas protection. And S5, the degreased beryllium-titanium powder blank pellets are sintered, and the beryllium-titanium alloy pellets with the diameter not smaller than 5 mm and the relative density not smaller than 98% are obtained.

A nested pebble bed blanket surrounding a fusion reactor's vacuum chamber includes stacks of nested pebbles composed of neutron multiplier shells filled with breeding spheroids. The shells have perforations passing through their inner and outer surfaces, and they include coolant distributor elements coupled or unitary with the inner surfaces that facilitates the coolant flow into the sphere, sweeping and cooling the inner breeding spheroids and the blanket as a whole. When bombarded by neutrons, the nested pebbles produce a fusion fuel to sustain fusion reactions and are replenished with conveyor systems. A separator extracts the fusion fuel from the blanket coolant, and the reactor's heat from the walls and nested pebble bed is extracted by inert gases and conveyed to a thermal storage and / or a power cycle

The application discloses a novel liquid metal and water interaction experimental device in the field of neutron multiplication reactors, which comprises a reaction assembly, a water passing assembly, a liquid metal assembly and a recovery assembly, wherein the reaction assembly provides an experimental environment for the liquid metal and water interaction; the water passing assembly is located above the reaction assembly; the liquid metal assembly is connected with the reaction assembly; the recovery assembly is connected with the bottom of the reaction assembly; and the pressurizing assembly is arranged on the reaction assembly, the water passing assembly, the liquid metal assembly and the recovery assembly; the liquid metal after the reaction can be recovered through the recovery assembly, so that the liquid metal after the experiment is prevented from flowing back to the liquid metal assembly and polluting the unreacted liquid metal, and the discharge assembly is arranged, so that the device is safer to use.

The invention discloses a high-density nano-microporous tritium breeding-neutron multiplication composite functional ceramic material as well as a preparation method and application thereof, and relates to the field of nuclear fusion engineering. The material is composed of high-density microporous lead lithium titanate ceramic pellets doped with titanium dioxide nanotubes, has high density and a nanoscale microporous structure, and is structurally a doped structure of Li2TiO3 and Li2PbO3 monoclinic crystals and the titanium dioxide nanotubes. According to the invention, the problem of low tritium desorption rate of traditional lithium titanate ceramic pellets is solved, and by regulating the doping ratio (0.1%-0.7%) of the titanium dioxide nanotubes, a nanoscale microporous structure is formed while high density is maintained, so that the mechanical property and the tritium desorption rate of the ceramic pellets can be synergistically improved. The prepared ceramic pellet has excellent mechanical strength, thermal stability and tritium release performance, and is suitable for a tritium breeding agent in a fusion reactor solid water-cooled cladding.

The invention discloses a tritium cladding, and the tritium cladding comprises a cladding with an inner cavity which is used for placing a neutron multiplier; the tritium breeding unit is filled with a neutron multiplication agent and a lithium breeding agent, and the tritium breeding unit is used for mixing the lithium breeding agent and the neutron multiplication agent to the maximum extent; the tritium extraction unit is used for extracting tritium from the cladding; and the heat dissipation unit is used for heat dissipation of the cladding. The propagation cylinder is arranged in the cladding, and the propagation material is also put into the propagation cylinder for tritium propagation, so that the mixing degree of the two propagation materials is improved, the reduction of the proportion of the propagation material caused by the occupation of the propagation cylinder in the space of the inner cavity can be reduced as much as possible, and the high proportion of the propagation material is ensured. Therefore, the tritium proliferation rate can be improved.

The application discloses a kind of multi-parameter nuclear data adjustment methods of fast reactor, first, for the multiple critical measurement experiments of existing zero-power experimental device, control rod value measurement experiment and cavitation reactivity measurement experiment, the χ coefficient and IS factor of all experiments are calculated respectively, and with a certain experiment as benchmark experiment, the similarity coefficient of all experiments and benchmark experiment is calculated, according to the screening criterion corresponding to similarity coefficient, χ coefficient and IS factor, select the experiment that can be used for nuclear data adjustment, second, using the measurement results of the experiment screened out, including effective neutron multiplication factor, control rod value and cavitation reactivity, based on Bayes theorem, nuclear data is adjusted, finally, three judgment criteria are used to screen the adjusted nuclear data, and the unreasonable nuclear data is discarded or limited range, finally, the adjusted nuclear data is obtained.The more accurate nuclear data is obtained, so as to improve the core physical calculation precision and confidence of fast reactor.

A nested pebble bed blanket surrounding a fusion reactor's vacuum chamber includes stacks of nested pebbles composed of neutron multiplier shells filled with breeding spheroids. The shells have perforations passing through their inner and outer surfaces, and they include coolant distributor elements coupled or unitary with the inner surfaces that facilitates the coolant flow into the sphere, sweeping and cooling the inner breeding spheroids and the blanket as a whole. When bombarded by neutrons, the nested pebbles produce a fusion fuel to sustain fusion reactions and are replenished with conveyor systems. A separator extracts the fusion fuel from the blanket coolant, and the reactor's heat from the walls and nested pebble bed is extracted by inert gases and conveyed to a thermal storage and / or a power cycle

The invention discloses a reactor core fuel element design method and device, and the method comprises the steps: obtaining the initial design parameters of a fuel element, the initial design parameters comprise the structural parameters of the fuel element, the design parameters of coated dispersion particles, and the tolerance range of the target nuclide loading capacity; determining a target loading capacity of a target nuclide according to the design parameters of the coated dispersion particles and physical parameters of the target nuclide; creating a fuel particle distribution model according to the design parameters of the coated dispersion particles; according to the target loading capacity of the target nuclide, the fuel particle distribution model and the structural parameters of the fuel element, determining the uncertainty of the reactor core neutron effective multiplication factor; according to the uncertainty, the target nuclide loading capacity is adjusted within the tolerance range, and target design parameters of the reactor core fuel element are obtained. Therefore, the uncertainty of the reactor core is reduced.

A target irradiation apparatus for producing radioisotope sources is provided. The target irradiation apparatus comprises a containment vessel, a plurality of electronic neutron generator inserts and a removable neutron enhancement cartridge. The containment vessel comprises an inner surface, an outer surface, a first end, a second end, a body section, and a support member. Each of the plurality of electronic neutron generator insert devices is inserted into one of a plurality of openings of the body section while the removable neutron enhancement cartridge is adapted to be positioned inside of the containment vessel. A radioisotope production system comprising a target irradiation apparatus and a method for producing radioisotope sources are also provided.