326 results about "Neutron radiation" patented technology

A present invention provides an internal circulating irradiation capsule available for the production of iodine-125 and a related production method. The irradiation capsule filled with xenon gas has a lower irradiation part, an upper irradiation part, and a neutron control member. The lower irradiation part is inserted into an irradiation hole of a reactor core and irradiated with a large quantity of neutron directly. When neutron is radiated to the xenon gas, iodine-125 is produced from xenon gas. The upper irradiation part protrudes from the irradiation hole, and iodine-125 is transferred to the upper irradiation part by convection and solidified in the upper part. The neutron control member reduces neutron in the upper part to produce iodine-125 of high purity and radioactivity in a large quantity.

A portable survey instrument and methodology yield intensity of neutron radiation, intensity of gamma radiation, and a direction of impinging gamma radiation. The instrument uses a neutron detector surrounded by an essentially rectangular moderator with preferably four gamma ray detectors disposed symmetrically about the neutron detector and within the moderator. Material and dimensions of the moderator are selected so that the neutron-measurement is equally sensitive to fast and thermal neutrons. The moderator also induces angular responses to the gamma ray detectors. Responses of the gamma ray detectors are combined to yield a parameter indicative of the angular position of a source. The survey instrument is portable and suited for hand held use.

A borehole logging system for determining bulk density, porosity and formation gas/liquid fluid saturation of formation penetrated by a borehole. Measures of fast neutron radiation and inelastic scatter gamma radiation, induced by a pulsed neutron source, are combined with an iterative numerical solution of a two-group diffusion model to obtain the formation parameters of interest. Double-valued ambiguities in prior art measurements are removed by using the iterative solution of the inverted two-group diffusion model. The system requires two gamma ray detectors at different axial spacings from the source, and a single neutron detector axially spaced between the two gamma ray detectors. The system can be embodied as a wireline system or as a logging-while-drilling system.

Normal tissue complications limit curative broadbeam radiotherapy to tumors including lung cancer. Radiation retinitis causing blindness limits quality of life and long term survival for patients with ocular melanoma. This invention pertains to alternative, normal tissue sparing 100 to 1,000 Gy microbeam radiations with least normal tissue complications and concomitant radio-immunotherapy by innate immune response of epidermis and dermis to low dose radiation with 50 kV X-rays. Total body skin radiation with former airport passenger screening machines with 50 kV X-ray is disclosed. Microbeams are generated without contaminating scatter and neutron radiations from collinear gamma ray and electron beam produced by inverse Compton interaction with high energy laser and electron beam and from proton and carbon ion beams in tissue equivalent cylindrical collimators. Extracorporeal immunotherapy and chemotherapy and apheresis of mutated subcellular particles released into circulation in response to cancer-therapies are by clinical continuous flow ultracentrifugation combined chromatography.

The present invention includes an apparatus and method for neutron radiation detection. The apparatus comprises combining thin walled, boron-coated straw tubes with a plastic moderator material interspersed around the tubes. The method involves using such an apparatus through application of voltage to a central wire running inside the tubes and collecting electrical pulses generated thereby.

An apparatus for estimating a property of an earth formation includes a pulsed neutron generator configured to emit a pulse of neutrons, a formation radiation detector configured to detect radiation emitted from the formation due to interactions with the pulse of neutrons, and a neutron generator radiation detector having a crystal structure and configured to detect a radiation particle emitted from the pulsed neutron generator and to provide a location within the neutron radiation detector at which the particle was detected. The crystal structure includes a plurality of detection cells, each detection cell having at least two electrically conducting columns with an applied potential difference such that electrons generated in the crystal structure by interaction with the radiation particle are collected by at least one of the electrically conducting columns to provide detection locations. A processor estimates the property using the detected formation radiation and the detection locations.

The invention discloses a laminated neutron radiation shielding composite material and a preparation method thereof; the laminated neutron radiation shielding composite material is in a three-layer composite structure, wherein a bottom layer is a polyethylene fiber reinforced epoxy resin matrix, a middle layer is a boron fiber reinforced epoxy resin matrix, and an upper layer is a polyethylene fiber reinforced epoxy resin matrix which is grafted with acrylic lead. The epoxy resin matrixes comprise materials basically in the following weight portions: 100 portions of bisphenol A epoxy resin, 8 portions to 15 portions of imidazole curing agent and 3 portions to 7 portions of silane coupling agent. In addition, boron carbide (B4C) which occupies 5 weight percent to 20 weight percent of the total weight of the epoxy resin is added into the epoxy resin matrix on the bottom layer; and lead oxide which occupies 10 weight percent to 30 weight percent of the total weight of the epoxy resin is added into the epoxy resin matrix on the upper layer. The laminated neutron radiation shielding composite material is specially manufactured to overcome the defects of a traditional neutron radiation shielding composite material that slowing and absorption functions are not separated so that the functions of an absorbing body cannot be displayed well.

The invention belongs to the field of radiation detection and relates to a method for monitoring the neutron radiation environment by using SRAM memorizers. The method includes the following steps that 1, neutron radiation calibration is conducted on SRAM memorizers different in types respectively, and a relation curve of the data flipping number and the neutron fluence are drawn; 2, the N type SRAM memorizer with the data flipping number keeping a linear relation with the neutron fluence is screened out, and the slope of the fitting curve serves as the neutron single ion effect flipping section of the N type SRAM memorizer; 3, the N type SRAM memorizer is placed in a to-be-monitored neutron radiation environment, and a relation curve of the data flipping number and the neutron fluence is drawn. According to the method, the linear and non-threshold characteristics of the neutron single ion flipping effects of the SRAM memorizers are made use of, neutron fluence monitoring in a reactor, a neutron accelerator and other neutron radiation environments is achieved, and experimental results show that the method can still maintain high measurement when the neutron fluence is very low.

The invention aims at providing a compensation type neutron dose instrument which comprises a packaging layer, a slowing-down sphere body and a heavy metal layer, wherein the slowing-down sphere body is arranged in the packaging layer, a neutron fission multiplication layer is arranged between the slowing-down sphere body and the packaging layer, the heavy metal layer is arranged in the slowing-down sphere body, a counter is arranged in the heavy metal layer, and an air rod is arranged in the slowing-down sphere body along a radial direction. According to the invention, neutron fluence response in a heat energy region can be improved, the neutron fluence response in an intermediate energy region can be correspondingly reduced, and accompanying Gamma rays in a neutron radiation field can be shielded.

The gas phase doping zone molten-silicon monocrystal production method includes the following steps: (1) charging and vacuum-pumping; (2). preheating silicon rod; (3) melting material; (4) doping, setting gap flow control parameter on the doping gas control device; (5), joining seed crystal by fusion; (6) leading crystal; (7) growing thin nack; (8) shouldering; (9) isodiametric growing; (10) ending and draw-breaking; (11) stopping gas; and (12) stopping furnace and removing furnace. Said invention saves the neutron radiation doping process so as to shorten production period and reduce production cost, and reduce production procedure.

The invention relates to the radiometric technology and in particular to an optical fiber coupled radiation detector used for fast neutron measurement. The optical fiber coupled radiation detector used for the fast neutron measurement comprises a scintillation probe which is formed by blending of fast neutron sensitive materials and scintillating mediums, a transmission optical fiber and a photovoltaic sensitive component, wherein one end of the transmission optical fiber is inserted in the middle of the scintillation probe, the other end of the transmission optical fiber is connected with the photovoltaic sensitive component, and an optical wrapping layer of one part, arranged in the scintillation probe, of the transmission optical fiber is removed. The optical fiber coupled radiation detector used for the fast neutron measurement has the advantages of being simple in structure, small in size, strong in environment adaptability, capable of achieving on line real-time monitoring and the like, and can meet the demand of fast neutron measurement under complex and severe environment.

The invention provides a quick dry type neutron-shielding lacquer putty and a method for preparing the same. The quick dry type neutron-shielding lacquer putty is used for filling a hole or an aperture of a neutron radiant point shielding structure in order to reduce the leakage of neutron radiation and improve the whole protective performance of a shielding system. The material is prepared by adopting a coagulant, a neutron moderator, a neutron absorber, a colorant, water and other compositions mixed together. The quick dry type neutron-shielding lacquer putty has good neutron-shielding performance, short drying time, simple structure, convenient construction, strong practicability and good economical benefit.

A radiocactive waste containing medium is circulated within two or more systems (1,2,3) separated from each other flowtechnically; and the circulated radioactive waste is exposed to neutron radiations of different energy spectrum in each system by operating a reactor physically united entirety of irradiated sections of the said systems as a nuclear reactor or an accelerator driven subcritical system. Each system (1,2,3) has a heat exchanger (9,10) and, in given cases, a circulating pump (10,21) and an expansion tank (5,16,27). The disclosed apparatus has two or more reactor regions (1,2,3) separated from each other by partitions (37,38) and, preferably, arranged coaxially within a reactor space encircled by a common shell structure (39). A particle beam (45) produced by a particle accelerator is preferably directed into the innermost reactor region (3).

The invention discloses a method for manufacturing a steel ingot used for million-kilowatt nuclear power reactor core structural component, austenitic stainless steel ingot that weighs over 25 tons is manufactured by electroslag remelting process: firstly, preparation: a single-phase bipolar series connected or triphase bipolar series connected electroslag remelting furnace is adopted; a copper wall water-cooling crystallizer and a water-cooled base plate are adopted; a consumable electrode is assembled; slag charge is matched; SiGa and Al powder are adopted for deoxidation; secondly, refinement and fusion casting: a graphite electrode is picked up and replaced by the consumable electrode to remelt the fully melted slag charge after slagging and slugging. When the actual weight of the steel ingot is 2 tons less than the preset weight, the electric power is reduced and feeding operation in telophase is carried out; thirdly, the steel ingot is stripped. The steel ingot manufactured by the invention has extremely high purity, extremely fine uniformity, excellent high temperature resistance and tarnish resistance, as well as strong anti neutron radiation embrittlement sensibility.

The invention relates to the field of nuclear radiation screening and protecting, and particularly relates to a high-temperature resisting shielding material with a neutron shielding effect, which is used for screening and protection of neutron radioactive sources such as isotopic neutron source, nuclear reactors, accelerators and the like. The material comprises the following components parts by weight: 40 to 50 parts of basis material, 40 to 50 parts of curing agent, 5 to 10 parts of wild phase particles, and 1 to 5 parts of modified particles. The material has a strong irradiation resisting performance, has a strong mechanical property, is used for screening and protecting to neutron radiation, and can bear the high temperature which is more than 200 DEG C.

The invention discloses an eliminating method of error in omission of dosage equivalent meter around neutron in the pulse neutron radiation field or strong neutron radiation field applying technical domain, which is characterized by the following: utilizing charge quantity output by BF3 proportional pipe to be direct ratio to energy loss of electric particle in the pipe to test over two neutrons; increasing the output pulse amplitude; connecting multiple discriminators at the back of the equivalent meter to correspond to overlapped threshold of one, two and three neutrons; transmitting the output pulse of different discriminators into microprocessor; calculating the real dosage equivalent according to the probability of the overlapped energy spectrum; correcting the omission number. The invention is easy to process data with simple structure, which can correct the omission number effectively.

The invention aims to disclose an ambient neutron dose equivalent meter. The ambient neutron dose equivalent meter is characterized by comprising a neutron probe, a neutron energy response adjustor and a control system, wherein a neutron detection element is arranged in the neutron probe, the neutron detection element is europium-doped lithium iodide scintillation crystal, the signal output end of the neutron probe is connected with the signal input end of the control system, and the neutron probe is placed at the position of the geometric center of the neutron energy response adjustor. Because the photomultiplier with high sensitivity is used as a photoelectric converter, the meter has light weight, portability, sensitive neutron response and good angle response, can accurately measure the ambient neutron dose equivalent level, has sound and light alarm function, is used for ambient neutron radiation monitoring of large nuclear facilities such as reactors, high-energy particle accelerators and the like, ensures neutron radiation safety of the ambient and the public, and fulfills the purpose of the invention.

The invention provides a method of performing fast neutron detection or spectroscopy comprising selecting at least one isotope which exhibits fast neutron-induced charged particle reactions, selecting a host medium capable of performing radiation energy spectroscopy, combining the isotope and host medium into an interactive spectroscopic combination, exposing the combination structure to radiation comprising fast neutrons to provide a spectroscopic output, which includes at least one peak in the pulse-height spectrum whose height and amplitude correlate to the energy and intensity respectively of the incident neutrons; and processing the output to detect or to provide measurements of the energy and intensity of incident fast neutron radiation. The invention also provides a fast neutron spectrometer for use with the method.

Disclosed is a dosimeter (1) for the detection of neutron radiation within an energy range of 0.025 eV to several hundred GeV, comprising a substantially spherical base body (3) which is used as a moderation body and which comprises hydrogenous material, a detection element (5) which is arranged in the center of the base body (3), and a neutron converter (7) surrounding the detection element (5). The neutron converter (7) comprises metal atoms which convert the energy of the high-energy neutron radiation essentially into neutrons within a suitable energy range. The dosimeter (1) is characterized in that the base body (3) is provided with an access (19) through which the detection element (5) can be introduced into the neutron converter (7) and removed thereform, and in that the neutron converter (7) is embodied in the form of a cylinder.