100 results about "Neutron diffraction" patented technology

The invention discloses a neutron diffraction residual stress determination device and a method. The device is characterized by using the reactor neutron source, carrying out monochromatization by a monochromator to obtain a required monochromatic neutron beam at a certain wavelength, and using the neutron beam to detect the residual stress. According to the invention, because the neutrons are uncharged, and when the neutrons interact with substance, the neutrons have no effect with extranuclear electons, charge Coulombian force obstacle has no need to overcome, thus low energy neutrons can enter in atoms; the neutron absorption of great majority of materials is low, thus the penetration depth of incoming neutron beam is deep. Simultaneously by collimator and slit collimation, the limitedneutron beam has high space resolution ratio, a three-dimensional lossless and deep stress test of a test piece is realized by translation of three directions which are vertical to each other and rotation around testing central point, and the defect that an X-ray and a synchrotron radiation residual stress determination device can only losslessly determine the residual stress of the crystal material surface and subsurface is overcome.

The invention discloses an in-situ stress-temperature loading device for a neutron diffraction technology. A frame in the device is designed into a door frame type structure, a hollow-shaft servomotor is utilized for driving multiple stages of gears with the same specification and the size to rotate via a speed reducer, and the horizontal motion operation of a test sample can be further realized through a guide component and a clamp. By controlling the forward rotation (reverse rotation) of the hollow-shaft servomotor, bidirectional synchronous drawing (compression) of the test sample is realized; and by controlling the rotational speed of the hollow-shaft servomotor, the speed regulation of drawing (compression) of the test sample is realized. A cavity type high-temperature furnace with the design based on a resistance heat radiation structure is matched with the frame to use, a temperature control instrument is used for controlling the temperature in a body cavity of the high-temperature furnace, fan-shaped through holes are respectively formed in the neutron incidence direction and the scattering direction, and quartz glass is further used for sealing. The in-situ stress-temperature loading device for the neutron diffraction technology, disclosed by the invention, can be used on a variety of neutron scattering (diffraction) spectrometers for realizing the neutron scattering (diffraction) in-situ stress-temperature loading testing technology.

The invention discloses an anti-thermal neutron radiation shielding material and a preparation method thereof. The anti-thermal neutron radiation shielding material is prepared by the following steps of: using rubber with radiation resistance as a matrix material; adding an anti-radiation additive which can shield thermal neutrons, a reinforced carbon black assistant and a processing assistant; and performing technical processes of a, mixing the rubber matrix, b, rolling and pre-forming the rubber matrix, c, vulcanizing and forming the rubber matrix, and the like to prepare the material. The anti-thermal neutron radiation shielding material provided by the invention has the shielding performance for the thermal neutrons, further, is good in flexibility, can be attached to the appearances of devices or apparatuses, and can be applied to surface protection of detectors such as a neutron diffraction spectrometer and the like and neutron protection of special curves.

The invention discloses an anvil cell high pressure device for the in situ neutron diffraction, which mainly comprises a frame, an inner pressure cavity, pressing anvils, a sealing cushion and a loading system, wherein the inner pressure cavity is positioned in the frame and is formed by a pressure head and a cavity seat; the pressing anvils are positioned in the inner pressure cavity and are respectively arranged on the pressure head and the cavity seat; anvil surfaces of the two pressing anvils are opposite; the sealing cushion is positioned between the two pressing anvils; a sample high pressure sealing cavity is formed by the two pressing anvils and the sealing cushion positioned between the two pressing anvils; the inner pressure cavity is provided with a neutron beam incident light channel and a diffraction light window; the loading system is provided with two stages of loading subsystems; primary loading subsystems are screw thread pair mechanical loading systems which are symmetrically arranged in pairs; a secondary load subsystem is formed by an oil cylinder arranged on the frame and a piston acts on the inner pressure cavity; and the high pressure device is suspended below a suspension device matched with a neutron reactor source platform through the frame. The anvil cell high pressure device has good compatibility between the pressing anvils and can be used for carrying out loading pressure application on an experimental sample on an experiment table. The loading pressure can be kept for a long time. Experimenters can be far away from the experiment table to carry out experimental operation. The anvil cell high pressure device has high safety.

The invention belongs to the field of nondestructive detection and relates to a method for nondestructive evaluation of residual stress levels in an aluminum alloy forged piece through ultrasonic waves. According to the method, the phenomenon that the propagation speed of the ultrasonic waves in materials can be affected by stress in the materials to a certain extent is used, and the difference of residual stress levels among different positions in the large size aluminum alloy forged piece is reflected through changes of sound speeds. The method has the advantages of being high in detection speed, large in measuring depth, good in economy and the like. The residual stress in the large size aluminum alloy forged piece is measured through the sound elastic effect of the ultrasonic waves in the method, and the method has the advantages of being high in measuring speed, convenient to use, flexible in measuring range, good in economy and the like. The single-time measuring time of the method is about five minutes and is shorter that the single-time measuring time of a neutron diffraction residual stress measuring method, the detection speed is high, the maximum measuring depth of the method can reach 400 mm, is larger that the measuring depth of the neutron diffraction method, and is much larger that the measuring depth of an X-ray method or a Barkhausen noise method.

The invention discloses an image fusion device and method based on period diffraction correlated imaging. The image fusion device comprises a fake thermal light source module, a transmission module, a detection module and a later-period solving module, wherein the transmission module comprises a signal path and a reference path, and the detection module comprises a first detector and a second detector. The image fusion device method comprises the steps that the fake thermal light source module gives out a light beam, part of the light beam is directly received by the second detector through space transmission, the other part of the light beam irradiates a target object, the light beam which penetrates through the target object is received by the first detector through transmission, output of the second detector and output of the first detector are sent to the later-period solving module, and the later-period solving module recovers an image of the target object through correlated calculation. According to the image fusion device and method based on period diffraction correlated imaging, calculation is easy and convenient, the cost is low, flexibility is high, and anti-interference performance is good.

The invention discloses a device for generating ultrahigh pressure. The device is capable of carrying out X light diffraction experiment, especially neutron diffraction experiment, is capable of integrating multiple measurement means, such as electrical transportation and spectra. The device comprises a primary pressure cavity, a secondary pressure cavity formed by eight secondary anvils, a sealing pad capable of penetrating through X light or neutron, a high-temperature and high-pressure assembly capable of being put into a space formed by the end surfaces of the anvils and the sealing pad, and a steel ring for supporting the eight secondary anvils, wherein the primary pressure cavity is driven by a belt-type press and formed by upper and lower tungsten carbide anvils; the steel ring is provided with an incident window and an emergent window. The device integrates the advantages of an opposite-anvil small press and a slide block-type multi-anvil large press, has the advantages that the opposite-anvil press is small and flexible and the multi-anvil large press is capable of providing enough lateral support and a relatively large sample size, and is very suitable for integration of in-situ X light / neutron diffraction experiment and measurement means, such as electrical transportation and spectra. The device has the advantages that the generated pressure is high, a large-size sample cavity is formed and multiple in-situ tests can be carried out.

The invention relates to an in-situ neutron diffraction stress and texture composite test method, wherein an in-situ environment loading device, a three-dimensional coordinate adjustment rotation table and a total station positioning system are used, the precise positioning of a specimen and the composite loading of the tilting function, the force load and the temperature field in in-situ test areachieved, and an in-situ neutron diffraction spectrum is collected with a neutron stress spectrometer. According to the in-situ neutron diffraction stress and texture composite test method, a specimen is positioned by using the aligning state of the focal point of a neutron beam, the visual field intersection point of dual total stations and the to-be-tested point of the specimen as basis, and the aligning state of the specimen and the neutron beam spot is precisely adjusted through the three-dimensional translation and rotation of a three-dimensional coordinate adjustment rotation table,; continuous temperature change from room temperature to 1000 DEG C, 0-90 DEG inclination and 360 DEG rotation of the specimen under 0-50 kN tension / compression are achieved with an in-situ environment loading device; and in-situ environment loading device. According to the present invention, the in-situ neutron diffraction stress and texture composite test method is suitable for the composite test ordetection of the neutron stress and texture of crystal materials or small engineering parts under the in-situ force thermal tilting loading.

Belonging to the technical field of measuring and testing, the invention relates to ultra-high cycle fatigue of an ultrasonic fatigue test simulation material, and a high temperature alloy ultra-high cycle fatigue damage simulation method adopting a microanalysis technique for studying micromechanical properties and material deformation to conduct damage assessment. In the invention, a neutron diffraction method is employed to test high temperature alloy funnel-shaped sample surface and subsurface residual stress absolute difference, thus obtaining a relation curve of a cycle number and the residual stress absolute difference; utilizing a nanoindentor to test the elastic modulus absolute difference between dendrite arms and dendrites in the material, thus obtaining a relation curve of the cycle number and the elastic modulus absolute difference; and analyzing the crystal deformation condition by electron back scattering diffraction so as to obtain a relation curve of the cycle number and small angle subboundary crystal deformation. Through comprehensive comparison of the three curves, the dominant factors determining high temperature alloy ultra-high cycle fatigue damage can be understood clearly, and the ultra-high cycle fatigue damage condition of similar other alloys can be predicted.

Wherein, first preparing the glass-ceramic; adjusting the neutron monochromator to select opposite monochromatic neutron; irradiating sample surface with neutron beam with diffraction angle 2theta as 10-75Deg; taking strain detection crystal face with principal crystalline phase as beta-wollastonite and obtaining the average strain result as: ªŠ=1 / 3(ªŠ11+ªŠ22+ªŠ33), opposite volume mean strain as í¸=1 / V(íʪŠdV); calculating with formulaªÊ=E / 3(1-2ªÈ)í¸ (wherein, E: Young's modulus; ªÈ: Poisson's ratio), and then obtaining the total strain on three axial directions ªñ=ea+eb+ec; exactly, here, selecting E=70GPa and ªÈ=0.245; repeating former steps to obtain different residual strain values to draw distribution curve. This invention can obtain the inner strain of sample and fit to massive sample.

A sample table of a neutron diffraction stress spectrometer is provided. The sample table includes a sample mounting plate, a horizontal movement system controlling horizontal movement of the sample mounting plate, a vertical lifting and descending system controlling vertical movement of the sample mounting plate, and a rotation movement system controlling rotation of the sample mounting plate, a neutron diffraction stress spectrometer detector and a capturer. The sample mounting plate is disposed on the horizontal movement system. The lower part of the horizontal movement system is connected to the vertical lifting and descending system. The vertical lifting and descending system is connected to the rotation movement system. The bottom of the rotation movement system is connected to a floating supporting system. The rotation movement system includes a sample table autorotation part, a sample table supporting mechanism and a swing and connecting part. The sample table autorotation part is used for controlling the sample mounting plate to rotate around the center axis. The swing and connecting part is mounted to the sample table supporting mechanism through a circular-arc guide rail, and is used for connecting the detector and the capturer, and moves along the circular-arc guide rail.

The invention discloses a method for measuring residual stress of nickel-aluminum bronze by utilizing a neutron diffraction method, which is used for measuring phase-to-phase stress between an alpha phase and a Fe3Al phase in nickel-aluminum bronze alloy caused by the deformation. The method comprises the following steps: step 1, preparing a nickel-aluminum bronze alloy tensile sample; step 2, selecting measuring parameters of neutron diffraction; step 3, in-situ measuring lattice distortion of a material; and step 4, calculating a second category of residual stresses. According to the method, the residual stress value of a copper basal body and the Fe3Al phase is obtained by utilizing the neutron diffraction method, a method for controlling the phase-to-phase stress of the nickel-aluminum bronze by utilizing the deformation is proposed, different residual stresses in different directions are produced between the alpha phase and the Fe3Al phase by loading and unloading different tensile stresses, and a variation trench and a numerical value of different residual stresses of the two phases under different loading situations can be obtained.

A gas laser device is presented that produces a near diffraction limited round beam exiting the discharge vessel. Through the use of a simple focusing system, additional waveguide strip and a spatial filter in conjunction with the new asymmetric hybrid planar waveguide resonator, a round diffraction limited beam can be produced exiting the discharge vessel. Furthermore, a second and very similar design is presented that allows for spatial filtering to take place directly outside of the discharge vessel, thereby enabling filtering of the beam to be an added option.

The invention discloses an in-situ X-ray CT imaging device for a neutron diffraction spectrometer. The in-situ X-ray CT imaging device comprises a fixed seat, a nanometer focus X-ray tube, an X-ray detector, a sealing container and a movable structure; the nanometer focus X-ray tube and the X-ray detector are arranged at two opposite sides of the fixed seat; the movable structure is arranged at the fixed seat in a sliding manner, the sealing container is arranged at the mobile structure, a sample is held in the sealing container, a neutron generator produces a neutron beam, and an included angle between an axis of the neutron beam and the axis of the nanometer focus X-ray tube is 45 DEG, the X-ray penetrates the sample and is detected by the X-ray detector, thereby performing real-time three-dimensional imaging on the sample. The simultaneous performing of the X-ray imaging and the neutron stress measurement can be satisfied, the mutual interference is avoided, expansion size and internal defects of the sample can be measured through the X-ray imaging technology, and the non-contact expansion factor measurement and the real-time internal defect measurement are realized.

The invention belongs to the technical field of neutron diffraction and discloses a neutron diffraction zero-substrate sample chamber which is made from titanium-zirconium alloy, wherein the weight proportion of titanium and zirconium is 65 to 69 percent of the zirconium and 31 to 35 percent of the titanium. Therefore, the sample chamber eliminates the interference caused by the prior stainless steel or quartz sample chamber on diffraction information of samples, and improves the reliability of diffraction data.

The invention relates to a neutron diffraction high-temperature goniometer and a special mechanical loading device thereof and belongs to the field of mechanics performance testing of materials. The neutron diffraction high-temperature goniometer comprises a high-temperature goniometer unit and a special mechanical loading unit, wherein the goniometer unit enables a mechanical loading system unit to rotate, and a tilted rotation operation at 0-90 degrees can be realized on a test piece; the mechanical loading system unit also can implement a free rotation operation on the test piece at 0-360 degrees around the axis of the mechanical loading system unit, and a need for different diffraction angles is met; the mechanical loading system unit integrates a halogen heating lamp, a grating scale and the like, heats the test piece and measures the deformation generated by the test piece; a control system unit can realize online real-time adjustment of goniometer parameters, mechanical loading indexes, heating temperature, etc. The invention has the advantages that the device can realize accurate control on the rotation of a measured sample in two directions under a mechanical loading condition; stepless closed-loop temperature control on the measured sample from room temperature to 1,000 DEG C can be realized under a condition of meeting the requirement on the beam angle of a neutron diffraction stress spectrometer.

The invention belongs to the technical field of neutron diffraction, and relates to a molybdenum-titanium alloy neutron transparent material used for a neutron diffraction high-pressure cavity sealing pad and a preparation method thereof. The molybdenum-titanium alloy neutron transparent material comprises 46 wt%-56 wt% of molybdenum and the balance titanium. Compared with an existing Ti-Zr alloy sealing pad, the molybdenum-titanium alloy neutron transparent material is high in strength and capable of improving the pressure of a high-pressure cavity and increasing the quantity of high-pressure experiment samples; the neutron transmittance of the molybdenum-titanium alloy neutron transparent material is high, the neutron diffraction performance of the molybdenum-titanium alloy neutron transparent material is equivalent to that of Ti-Zr alloy, but the adhesion of the molybdenum-titanium alloy neutron transparent material to diamond is very low; and a diamond anvil cell is easy to clean after a high-pressure experiment, the service life of the diamond anvil cell can be prolonged, and the high-pressure experiment cost is reduced.

The invention discloses a neutron diffraction method for welding residual stress of a duplex stainless steel thick plate. The method comprises the following steps: determining stress testing crystal faces in different directions and a wavelength changing manner, so that a penetration depth of the neutron in the duplex stainless steel thick plate is increased, and testing time and testing errors are reduced; accurately calculating a two-phase ratio in a standard volume of the neutron diffraction test by virtue of transformation of diffraction peak intensity; and simultaneously testing two-phasestresses under specific equipment and diffraction conditions. According to the method disclosed by the invention, the penetration depth of the neutron can be effectively improved by virtue of a variable wavelength manner; the residual stress time of the duplex stainless steel thick plate in the neutron diffraction test can be reduced; the testing error of the residual stress of the duplex stainless steel thick plate can be reduced; the two-phase ratio in the standard volume can be accurately calculated by utilizing data of the diffraction peak intensity obtained by the neutron diffraction; and the influence produced by micro stress caused by two-phase performance mismatching is clear, and macro welding residual stress distribution of the duplex stainless steel is accurately calculated.

The invention provides a pressure loading device for high-pressure neutron diffraction. The device comprises an anvil assembly. The anvil assembly comprises an upper anvil and a lower anvil with opposite anvil surfaces, the anvil surfaces of the upper anvil and the lower anvil are respectively sunken inwards relative to the axial directions of the upper anvil and the lower anvil to form an arc-shaped upper anvil surface and an arc-shaped lower anvil surface. The pressure loading device also comprises a sealing gasket assembly and a diamond pressurizing sheet, wherein the sealing gasket assembly is arranged between the two anvils, a pressure cavity is defined by an inner cavity of the sealing gasket assembly, the upper anvil face and the lower anvil face, and the diamond pressurizing pieceis arranged in the inner cavity of the sealing gasket assembly and divides the pressure cavity into an upper pressure cavity body and a lower pressure cavity body.

The invention provides a method for testing residual stress of a thick plate by a neutron diffraction technology. According to the method, in allusion to crystal structures and elemental components ofdifferent test materials, corresponding relationships among the Bragg edges, the total neutron absorption cross sections and the wavelengths of the test materials are calculated; through calculationof the corresponding relationships among the Bragg edges, the total neutron absorption cross sections and the wavelengths, several wavelength values which can increase the penetration depth of neutrons in a thick plate sample are determined; the texture of the sample is tested, a preliminary test wavelength according to a test result of the texture is selected, and corresponding optimal wavelengths of the test sample in a transmissive mode and a reflective mode are selected according to a peak height / background value, a strain error value, a total neutron count and the actual neutron penetration path length; through change of the wavelengths, the penetration depth of the neutrons in the thick plate sample is increased, the test time is shortened, a test error is reduced, and the residual stress of the thick plate is accurately tested. In a way of changing the wavelengths, the penetration ability of the neutrons in the thick plate sample is improved, the efficiency of testing the residual stress of the thick plate through neutron diffraction is improved, the test time is shortened and the test error is reduced.

The invention provides a high-precision probe clamping device for sampling positioning in neutron diffraction measurement. The device comprises a top plate, a base, a plurality of support connection columns, an upper positioning member and a lower positioning member, wherein the top plate and the base are arranged up and down; the support connection columns are vertically arranged between the topplate and the base; the upper positioning member and the lower positioning member are respectively arranged at center positions of the top plate and the base; coaxial and uni-diameter through holes are formed in the two positioning members to contain the upper and lower ends of a probe; a threaded hole matched with a fastening screw and communicated with the through hole in the corresponding positioning member is arranged on each positioning member; the threaded holes are horizontally arranged and located on the same side of the probe; through screw-in and screw-out of the fastening bolts, thetwo ends of the probe are clamped and loosened; and through rotating the positioning members along the thread direction to adjust the distance between the two positioning members, the straightening of the probe is realized. The device is capable of realizing rapid change and straightening operations for the probe under the premise of ensuring the mounting precision and verticality of the probe; and the probe is high in mounting precision and is beneficial for accurate positioning of samples.

The invention discloses a synthesizing method of deuterated octogen. The synthesizing method is characterized by comprising the following steps of enabling a deuterated formaldehyde matter and an ammonia compound to react, so as to obtain an intermediate, namely deuterated urotropine; further acetylizing and nitrifying, so as to obtain an intermediate, namely 1,5-diacetyl-3,7-binitro-1,3,5,7-teraazamacrocycle octane; using nitric acid / phosphorus pentoxide to nitrify, so as to obtain the product with high selectivity, namely deuterated octogen. The deuterated octogen synthesized by the method has the advantages that the purity is high, the deuterating rate is high, and the deuterated octogen can be applied to the fields of neutron diffraction, energetic material study, analysis and detection, and the like.

The invention discloses a focusing device for monochromatic neutrons. The device is a vertical focusing device for the monochromatic neutrons used for a neutron diffraction spectrometer, and comprisesa frame, a vertical adjustment driving assembly, and a horizontal swing angle adjusting assembly. The vertical adjustment driving assembly is in an independent design and can independently adjust thevertical angle of a single wafer. The wafer fixing plate in the horizontal swing angle adjusting assembly is a cuboid with one end closed and the other open and can achieve the horizontal swing angleadjustment of the wafer fixing plate. According to the focusing device for the monochromatic neutrons, in the focusing adjustment for the monochromatic neutrons, the single wafer is provided with thefunctions of vertical focusing and horizontal swing adjusting, the beam spots are uniform, the neutron intensity can reach the optimum value, and the divergence of the beam spots caused by the difference between the reflection crystal plane and the surface included angle is effectively reduced, and the radiation dose of a personnel is reduced. The device is used with germanium mosaic crystals andthe neutron diffraction spectrometer, can monochromize the large-size white light neutron beams, focus to the sample position, and form into a concentrated monochromatic neutron beam, so that the intensity and the utilization rate of the neutrons are improved.

The invention discloses a high-temperature and high-pressure loading device for in-situ neutron diffraction. A groove is formed in an anvil in the device; a graphite tube is arranged in the groove; pressure transmission mediums I and II are arranged in grooves in the periphery of the graphite tube separately; a magnesium oxide tube is arranged in the graphite tube; a pressure transmission medium III and a titanium-zirconium ring are sequentially arranged on the periphery of the groove; a bakelite ring is arranged on the periphery of the anvil; the periphery of the titanium-zirconium ring and the bakelite ring are concentrically laminated; a steel ring is arranged on the periphery of the bakelite ring; the bakelite ring and the steel ring are concentrically laminated; a round hole is formed in one side of the center of the steel ring and a window is correspondingly formed in the other side; the round hole, the window and the center of the titanium-zirconium ring are located in the same horizontal line; and a thermocouple horizontally passes through the magnesium oxide tube. The high-temperature and high-pressure loading device is capable of generating a high-temperature and high-pressure sample environment and carrying out in-site observation by using neutron diffraction at the same time. Temperature and pressure calibration is carried out in the magnesium oxide tube, the generated high pressure is about 7GPa and the temperature is 1500K.

It is a neutron diffraction buildup image apparatus, which comprises calibrated neutron beam and detector and is characterized by the following: to locate monochromator along the forward direction of the calibrated neutron beam at an incidence angle Theta with the monochromator; to parallel lay an analyzer to the monochromator; the analyzer diffraction neutron beam is at a direction of the said detector ; to lay a aluminum lens at an angle of 45 degrees to the light axis translated by the detector; to locate a CCD cameral on the reflection path of the aluminum lens and the output end of the CCD cameral is connected with a display; the said detector, aluminum reflection lens and CCD cameral are tightly located in a dark case. The advantages of this invention are the following: it eliminates dispersion noise generated when neutron and nucleus act together and directly penetrate the neutron interference and improves the contrast and distinguishability of the neutron.

The invention discloses a method for representing internal stress of TATB-based PBX under a force-heat effect. The method for representing the internal stress of the TATB-based PBX under the force-heat effect comprises the following steps: loading mechanical stress / heat stress to the PBX in situ; using a neutron diffraction technology to obtain crystal lattice parameters of a TATB crystal so as toobtain relations between mechanical stress and a temperature and the crystal lattice parameters of the TATB; and meanwhile, using an internal microstructure representing technology to obtain a meso-structure of the PBX; obtaining a performance inflection point of the PBX by using the relations among the mechanical stress, the temperature and the crystal lattice parameters of the TATB and using the meso-structure; and finally, obtaining an internal TATB crystal response behavior rule of the PBX under the force-heat coupling effect. The method for representing the internal stress of the TATB-based PBX under the force-heat effect, disclosed by the invention, has the advantages that the neutron diffraction technology is introduced into the study field of energetic materials for the first time; lattice parameters, such as displacement, widening and asymmetry, of a TATB crystal diffraction peak in the PBX under the mechanical stress / heat stress is non-destructively observed in a non-invasive manner, so that basic parameters can be provided for macro-performance evaluation of the energetic materials.

The invention discloses a high-pressure hydrate generation device applicable to neutron diffraction. The device comprises a temperature loading system, a pressure loading device, a rotating mechanism,a hydrate reactor, an incidence window, a gas inlet pipeline, an emergence window and a hydrate sample cavity, wherein the hydrate reactor comprises a concentric cylinder I, a concentric cylinder IIand a concentric cylinder III which are arranged from inside to outside in a coaxial sleeving manner, and a piston chamber is arranged at the axis of the concentric cylinder I; the pressure loading device comprises a press, a piston and a pressure transfer medium, the piston chamber of the concentric cylinder I is filled with the pressure transfer medium, the hydrate sample cavity is made of a flexible material, immersed in the pressure transfer medium and connected with a gas inlet system through the gas inlet pipeline, one end of the piston is connected with the press, the other end extendsinto the piston chamber and can move axially, and the rotating mechanism is connected with the hydrate reactor. The device can conveniently study generation and decomposition processes of gas hydratesby use of neutron diffraction.

The invention relates to a tungsten-based neutron transparent material of a neutron diffraction high-pressure cavity and a preparation method thereof. The tungsten-based neutron transparent material comprises 68-78wt% of tungsten and the balance any one of titanium and manganese, or one or two of titanium hydride powder and manganese powder. Compared with the existing Ti-Zr alloy or stainless steel seal pad, the high-pressure cavity seal pad material has high hardness, large strength, high coherent scattering transparency and low adhesiveness, prolongs a service life of a diamond anvil cell and improves pressure in the high-pressure cavity.

The invention discloses a high-temperature in-situ loading stress measuring device for neutron diffraction. The device comprises a supporting frame, a left loading shaft, a right loading shaft, a heating assembly and a connecting rod; the left and right loading shafts penetrate the left and right sides of the supporting frame respectively, a sample soleplate is formed between the left and right loading shafts, the heating assembly comprises an induction coil which is composed of multiple helical form coils, a neutron scattering space is wound and reserved outside a sample, and the induction coil can heat the sample after being electrified; one end of the connecting rod is detachably connected with the supporting frame, and the other end of the connecting rod is detachably connected with one end of the left loading shaft; and when one end of the right loading shaft bearing an external force, the sample is stretched. The high-temperature in-situ loading stress measuring device is smallerin size and simpler in structure, can conveniently observe the condition of the sample in the experiment process, and can optimize creep flow experiment measurement when the sample is loaded at hightemperature, and further a stress strain measurement result is more accurate.