65 results about "Lanthanum bromide" patented technology

Scintillator materials based on certain types of halide-lanthanide matrix materials are described. In one embodiment, the matrix material contains a mixture of lanthanide halides, i.e., a solid solution of at least two of the halides, such as lanthanum chloride and lanthanum bromide. In another embodiment, the matrix material is based on lanthanum iodide alone, which must be substantially free of lanthanum oxyiodide. The scintillator materials, which can be in monocrystalline or polycrystalline form, also include an activator for the matrix material, e.g., cerium. Radiation detectors that use the scintillators are also described, as are related methods for detecting high-energy radiation.

Scintillator materials based on certain types of halide-lanthanide matrix materials are described. In one embodiment, the matrix material contains a mixture of lanthanide halides, i.e., a solid solution of at least two of the halides, such as lanthanum chloride and lanthanum bromide. In another embodiment, the matrix material is based on lanthanum iodide alone, which must be substantially free of lanthanum oxyiodide. The scintillator materials, which can be in monocrystalline or polycrystalline form, also include an activator for the matrix material, e.g., cerium. Radiation detectors that use the scintillators are also described, as are related methods for detecting high-energy radiation.

A gamma ray detector assembly for a borehole logging system that requires the measure of gamma radiation with optimized gamma ray energy resolution and with fast emission times required to obtain meaningful measurements in high radiation fields. The detector assembly comprises a lanthanum bromide (LaBr3) scintillation crystal and a digital spectrometer that cooperates with the crystal to maximize pulse processing throughput by digital filtering and digital pile-up inspection of the pulses. The detector assembly is capable of digital pulse measurement and digital pile-up inspection with dead-time less than 600 nanoseconds per event. Pulse height can be accurately measured (corrected for pile-up effects) for 2 pulses separated by as little as 150 nanoseconds. Although the invention is applicable to virtually any borehole logging methodology that uses the measure of gamma radiation in harsh borehole conditions, the invention is particularly applicable to carbon / oxygen logging.

Scintillator materials based on certain types of halide-lanthanide matrix materials are described. In one embodiment, the matrix material contains a mixture of lanthanide halides, i.e., a solid solution of at least two of the halides, such as lanthanum chloride and lanthanum bromide. In another embodiment, the matrix material is based on lanthanum iodide alone, which must be substantially free of lanthanum oxyiodide. The scintillator materials, which can be in monocrystalline or polycrystalline form, also include an activator for the matrix material, e.g., cerium. To further improve the stopping power and the scintillating efficiency of these halide scintillators, the addition of bismuth is disclosed. Radiation detectors that use the scintillators are also described, as are related methods for detecting high-energy radiation.

The invention relates to the technical field of radiation detection and provides a nuclide recognition device using lanthanum bromide to measure radioactive aerosol in the air. The nuclide recognition device comprises an aerosol detecting system, an air flow circuit system and an electric system. The aerosol detecting system comprises a gas sampling circuit, a lanthanum bromide detector and an automatic paper feed mechanism. The lanthanum bromide detector is fixed in a cavity formed by the gas sampling circuit. The automatic paper feed mechanism is disposed at the outlet of the gas sampling circuit. The gas sampling circuit comprises a rotary drum and filter paper fixed at two ends. The nuclide recognition device has the advantages that the lanthanum bromide detector is used to detect the gamma ray generated by the radioactive nuclide, nuclide recognition capability of the device is increased greatly, and environmental background can be removed easily.

The invention relates to a three-energy coal ash content online monitoring device which comprises a low-energy gamma source Am241, an intermediate-energy gamma source Cs137, and a lanthanum bromide detector for receiving the low-energy and intermediate-energy gamma rays, wherein gamma photons emitted by the low-energy gamma source Am241 and the intermediate-energy gamma source Cs137 irradiates the coal sample in a sample container; the output terminal of the lanthanum bromide detector is connected with the input terminal of a multi-channel data analysis spectrometer; the collected gamma energy spectrum information and the characteristic X-ray spectrum information are transmitted to a data processing and spectrum unscrambling system; and the data processing and spectrum unscrambling system is used for processing the data. The three-energy coal ash content online monitoring device can be used for coal sampling and automatic rapid detection of as-received coal vehicles without bypass belts, and can be mounted and detected only by slightly changing the structure of the rear end of the sample container.

A gamma ray detector assembly for a borehole logging system that requires the measure of gamma radiation with optimized gamma ray energy resolution and with fast emission times required to obtain meaningful measurements in high radiation fields. The detector assembly comprises a lanthanum bromide (LaBr3) scintillation crystal and a digital spectrometer that cooperates with the crystal to maximize pulse processing throughput by digital filtering and digital pile-up inspection of the pulses. The detector assembly is capable of digital pulse measurement and digital pile-up inspection with dead-time less than 600 nanoseconds per event. Pulse height can be accurately measured (corrected for pile-up effects) for 2 pulses separated by as little as 150 nanoseconds. Although the invention is applicable to virtually any borehole logging methodology that uses the measure of gamma radiation in harsh borehole conditions, the invention is particularly applicable to carbon / oxygen logging.

The invention relates to a portable multifunctional digital radiation inspection instrument which comprises a sodium iodide probe, a lanthanum bromide probe, a Geiger counter tube, a plastic scintillator probe, a BF3 probe, a multi-channel analyzer, a PDA and a computer host. The sodium iodide probe, the lanthanum bromide probe, the Geiger counter tube, the plastic scintillator probe and the BF3 probe are respectively connected to the multi-channel analyzer. The multi-channel analyzer is connected to the PDA and the computer host. The portable multifunctional digital radiation inspection instrument has the advantages of being simple in structure, small in size, convenient to carry, accurate and comprehensive in detection result and the like.

Scintillator materials based on certain types of halide-lanthanide matrix materials are described. In one embodiment, the matrix material contains a mixture of lanthanide halides, i.e., a solid solution of at least two of the halides, such as lanthanum chloride and lanthanum bromide. In another embodiment, the matrix material is based on lanthanum iodide alone, which must be substantially free of lanthanum oxyiodide. The scintillator materials, which can be in monocrystalline or polycrystalline form, also include an activator for the matrix material, e.g., cerium. To further improve the stopping power and the scintillating efficiency of these halide scintillators, the addition of bismuth is disclosed. Radiation detectors that use the scintillators are also described, as are related methods for detecting high-energy radiation.

The invention belongs to the field of engine lubricants, and relates to preparation of an extreme pressure anti-wearing additive and energy-saving environmental-friendly engine oil containing same. Preparation of the extreme pressure anti-wearing additive comprises the following steps: dissolving lanthanum bromide into distilled water, stirring till a clear and transparent liquid, dropping an ethanol solution containing polymeric ionic liquid modified graphene and sodium carbonate drop by drop under violent stirring, then the solution can be white and muddy immediately, implementing constant-temperature reaction, after reaction is completed, leaving to stand and precipitate, filtering, washing the precipitate for multiple times with distilled water, further washing for multiple times with absolute ethyl alcohol, finally washing for multiple times with a potassium tetrafluoroborate solution, implementing particle exchange, drying so as to obtain a sample, and grinding for later use. The energy-saving environmental-friendly engine oil containing the extreme pressure anti-wearing additive comprises basic oil, an anti-wearing agent, the extreme pressure anti-wearing additive, a high-temperature antioxidant, a clearing agent, a dispersing agent, a viscosity index improver, and the like. The engine oil designed from the extreme pressure anti-wearing additive is relatively good in bearing capability and extreme pressure anti-wearing property, and is relatively good in environmental-friendliness.

The invention discloses a preparation method of anhydrous lanthanum bromide, which comprises the following steps: (1) well mixing ammonium bromide with lanthana; (2) heating the mixture obtained in step (1) in closed environment with a certain leakproofness to obtain anhydrous lanthanum bromide. The method of the invention is easily available in raw materials, and low in cost; the preparation process is simple, short in flow, easy to control, high in product yield, and low in production cost; the prepared anhydrous lanthanum bromide is high in purity, and has a purity of up to 99.5%; and the preparation method can be used for preparation of lanthanum bromide scintillation crystals, and has very good industrial and commercial prospects.

The invention relates to a method for growing a cerium-doped lanthanum bromide scintillation crystal by using an out-of-phase seed crystal. The seed crystal made of a crystal material of which the structural parameters and symmetry are similar to those of a lanthanum bromide crystal is placed in a nucleation area at the bottom of a quartz crucible, the seed crystal material and lanthanum bromide are not subjected to chemical reaction, and the melting point of the seed crystal material is higher than that of the lanthanum bromide crystal. The crystal is grown by a crucible descending method, two-section temperature control is performed at the melting stage of a raw material to ensure that the upper part is cold and the lower part is hot, the convection effect of a melt is improved, the lanthanum bromide is nucleated on the surface of the seed crystal preferentially in the crucible descending process, the growth direction of the lanthanum bromide is consistent with the crystallographic direction of the seed crystal, and the lanthanum bromide crystal in the required direction is obtained by continuous growth. The method has the advantages that: a stable crystal material in air can be selected as the seed crystal, and the phenomenon that processing and anhydrous operation are difficult to perform when the lanthanum bromide crystal is taken as the seed crystal is avoided; and compared with a seed-crystal-free spontaneous nucleation growth method, the method has the advantage that: the success rate of oriented crystal growth is greatly improved.

The invention discloses a preparation method of a cerium-doped lanthanum chlorobromide scintillating crystal. The crystal is a solid solution crystal with excellent scintillating performance; and the molecular formula of the crystal is CexLal-xClyBr3-y, wherein x is more than 0 and less than 1; y is more than 0 and less than 3. In the method disclosed by the invention, a related halide crystalline hydrate with low cost is used as an initial raw material to be dissolved in water and react with SOCl2 and water to obtain a high-purity CexLal-xClyBr3-y polycrystalline raw material with even components at the room temperature; and then the polycrystalline is used as the raw material for growing of a CexLal-xClyBr3-y single crystal by using a crucible descending method. The method can be used for obtaining the CexLal-xClyBr3-y scintillating crystal with even components at a lower cost.

The invention discloses a low-cost weak radionuclide detecting method. Compared with an existing method, according to the method, firstly, a plastic scintillation spectrometer and a lanthanum bromide spectrometer form a double-coincidence detecting array structure, detecting efficiency, energy resolution, application cost and other factors are comprehensively considered, a lanthanum bromide detector is adopted as a main detector, a plastic detector is adopted as a coincidence detector, and an anticoincidence and coincidence measurement method is adopted for reducing the environmental background and increasing the system peak-to-compton ratio; secondly, front-end fast electronic circuit development and a subsequent digital processing algorithm are carried out on an electronic circuit of nuclear signal processing, pulse forming, base line restoration, overlapped pulse separation and the like are included, noise interference is reduced, and the energy resolution is increased; finally, a plastic scintillator is directly adopted as a shielding material of the main detector lanthanum bromide, therefore, the system weight can be reduced, and detecting efficiency can be improved.

The invention discloses a method for screening and treating output signals of a lanthanum bromide gamma spectrometer and application thereof, wherein the output signals are radiation signals of gamma ray and alpha particles. The method for screening and treating the output signals of the lanthanum bromide gamma spectrometer includes the steps of: using the lanthanum bromide gamma spectrometer to detect the radiation of an object to be detected so as to obtain the output signals; analyzing the output signals so as to obtain characteristic quantity of the gamma ray and characteristic quantity of the alpha particles; obtaining a distribution diagram of the characteristic quantity of the gamma ray and the characteristic quantity of the alpha particles along with energy based on the characteristic quantity of the gamma ray and the characteristic quantity of the alpha particles; and distinguishing the radiation signals of the gamma ray and the alpha particles in the output signals based on the distribution diagram, and obtaining an energy spectrum measurement value gamma[measurement] of the gamma ray and an energy spectrum measurement value alpha[measurement] of the alpha particles. The method can simply and effectively distinguish the radiation signals of the gamma ray and the alpha particles in the output characteristic quantity signals.

The invention discloses a double salt of XNH4Br.LaBr3.YH2O and a preparation method thereof. The method comprises: (1) well mixing hydrated lanthanum bromide with a molecular formula of LaBr3.mH2O with ammonium bromide, wherein m>0; (2) heating the mixture obtained in step (1) to obtain the double salt. The double salt of the invention is easy to dehydrate, is low in hydrolyzation degree in a heating dehydration process, and is suitable for preparing anhydrous lanthanum bromide with high purity.

The invention provides a growth method for lanthanum bromide scintillating crystal. The method comprises the following operations: loading raw materials into a crucible, putting the crucible into a fall furnace for heating and melting; keeping the crucible fixed and slowly moving the furnace body, so that the crucible passes through a temperature gradient area, the raw materials crystallize at the bottom of the crucible, and the crystal gradually grows along the direction same as motion of the furnace body along with continuous motion of the furnace body. By using the growth method provided by the invention, the crucible is fixed and crystal growth is achieved by virtue of the motion of the furnace body, impurities, such as inclusions and bubbles introduced by interference of micro-vibration of a down-lead device with crystal growth in a traditional LaBr3:Ce scintillating crystal growth method can be effectively avoided, the optical quality of the crystal can be significantly improved, and the growth method is especially suitable for growth of large-size and high-optical quality LaBr3:Ce scintillating crystal.

The invention discloses a neodymium-doped lanthanum bromide single crystal flash body and a preparing method thereof, which belong to the technical field of ray detection of inorganic flash bodies. The structure of the flash body is that light reflection materials are wound on the upper face and the lateral face of neodymium-doped lanthanum bromide crystal, an aluminum sheet is wrapped on the outside of the light reflection materials, quartz glass sheets are arranged on the bottom faces of the light reflection materials, and quartz glass sheets, the neodymium-doped lanthanum bromide crystal and the aluminum sheet are firmly adhered through transparent liquid glue. The neodymium-doped lanthanum bromide single crystal flash body can improve a LaBr3: Ce3+light-emitting area and enables the LaBr3: Ce3+light-emitting area to extend towards the long wave direction so that a photomultiplier responsive to the long wave is better matched with the LaBr3: Ce3+light-emitting area.

The invention discloses a method of measuring the neutron close rate by means of a lanthanum bromide detector, and a neutron close rate instrument. The method of measuring the neutron close rate can calculate and obtain the neutron close rate by utilizing the function relationship having determinacy between the net counting rate of the neutron characteristic gamma energy barrier, of a neutron, generated in the lanthanum bromide detector and the neutron close rate, at the point, of the neutron, by measuring the gamma energy spectrum, and by utilizing the function relationship having determinacy. Therefore, the method of measuring the neutron close rate by means of a lanthanum bromide detector can obtain the neutron close rate more conveniently, more quickly and more accurately.

The scintillator comprises a scintillator packaging shell, an optical window, a scintillator, a scintillator light emitting surface, a scintillator rear end surface, a scintillator side surface, an optical vibration reduction layer, a transparent coupling medium, a side surface light reflection layer, a first side surface vibration reduction assembly, a second side surface vibration reduction assembly, a scintillator rear end reflection layer, a rigid metal plate, a rigid vibration reduction device, a rear cover and an inert gas and high temperature soldersealing interface, a laser welding seam is formed between the rear cover and the scintillator packaging shell, the scintillator is alkali metal halide or rare earth halide, and the scintillator is one of cerium-doped lanthanum bromide, cerium-doped lanthanum chloride, thallium-doped sodium iodide and sodium-doped cesium iodide; the reserved space for thermal expansion of the scintillator and the packaging internal material prevents the scintillator from being damaged by high temperature, and inert gas is filled in the gap, so the influence of oxygen in the air on the reflecting material and the light guide material under the condition of high temperature can be effectively reduced, and stability of the light output performance of the scintillator is ensured.

A gamma ray detector assembly for a borehole logging system that requires the measure of gamma radiation with optimized gamma ray energy resolution and with fast emission times required to obtain meaningful measurements in high radiation fields. The detector assembly comprises a lanthanum bromide (LaBr3) scintillation crystal and a digital spectrometer that cooperates with the crystal to maximize pulse processing throughput by digital filtering and digital pile-up inspection of the pulses. The detector assembly is capable of digital pulse measurement and digital pile-up inspection with dead-time less than 600 nanoseconds per event. Pulse height can be accurately measured (corrected for pile-up effects) for 2 pulses separated by as little as 150 nanoseconds. Although the invention is applicable to virtually any borehole logging methodology that uses the measure of gamma radiation in harsh borehole conditions, the invention is particularly applicable to carbon / oxygen logging.

The invention discloses a waterless packaged scintillation crystal combination body. The combination body comprises a scintillation crystal, a shell and a window sheet. The window sheet and the shell are packaged and connected, and the scintillation crystal is sealed in an internal portion of the shell. The invention also discloses a waterless packaging method of the waterless packaged scintillation crystal combination body. The method comprises the following steps that the shell used for packaging a lanthanum bromide scintillator, an end cap, the window sheet, a lanthanum bromide crystal and a crystal lining are included; a thermal evaporation technology is used to process the shell and the end cap; a teflon material is used to make the crystal lining, a shape of the crystal lining is a cylinder whose one end is closed, and an internal portion can accommodate the lanthanum bromide scintillator; and a waterless vacuum cold pressing technology is used to seal the end cap and the window sheet. By using a packaging technology, the lanthanum bromide crystal is isolated from water vapor so that a problem that the lanthanum bromide crystal absorbs the water vapor and is easy to deliquesce is solved.

The invention discloses an airborne pod radiation environment monitoring device comprising a main control board and an industrial personal computer; the main control board is connected with the industrial personal computer through a wireless data transparent transmission module; the main control board is connected with a lanthanum bromide crystal through a digital multi-channel board and a photomultiplier; the main control board is connected with a NaI probe through the digital multi-channel board and the photomultiplier PMT; the main control board is connected with an integral acquisition board through the digital multi-channel board and the photomultiplier PMT; the main control board is connected with a plastic scintillator through the digital multi-channel board and the photomultiplierPMT, the main control board is also connected with a silicon PIN detector, and the main control board is also connected with an altimeter and a positioning module. The device has the beneficial effects that: 1, the measurement range of the pod type dose rate is wider, and the energy response linearity is good; and 2, nuclide measurement of the lanthanum bromide probe and the NaI probe realizes combination of high resolution and high detection efficiency.

The invention puts forward a method for measuring potassium 40 in environment via a lanthanum bromide detector and belongs to the field of radiation detection and radiation environment monitoring methods. The method comprises the following steps: radioactivity of the lanthanum bromide detector is calibrated, a background spectrum response y of the detector is obtained, the lanthanum bromide detector is used for measuring 40K in the environment, an energy spectrum response y* can be obtained via fitting operation, and activity of 40K in the environment can be calculated according to the background spectrum response y of the lanthanum bromide detector and the energy spectrum response y*. The method disclosed in the invention can be used for precisely measuring 40K in the environment.

The invention discloses a multi-crucible gradient condensation crystal growth device and a method for growing a large-size lanthanum bromide single crystal by using the same, relates to a device and method for growing the lanthanum bromide single crystal, and aims to solve the technical problems of poor single crystal quality and high cracking tendency in a conventional lanthanum bromide single crystal growth method. The device comprises a double-layer shell, a heat preservation cover, a lining ceramic tube, two groups of external heating coils, two groups of internal heating coils, a plurality of temperature control thermocouples, a plurality of crucible supports and a plurality of quartz crucibles, wherein the lining ceramic tube is arranged on the axis of the cylindrical double-layer shell; the plurality of crucible supports are uniformly distributed and fixed in an annular area between the double-layer shell and the lining ceramic tube; the two groups of external heating coils arearranged in the double-layer shell; the two groups of internal heating coils are arranged on the lining ceramic tube. The method comprises the steps: packaging lanthanum bromide seed crystals in the quartz crucibles, putting the quartz crucibles on the crucible supports, and carrying out full-static in-situ gradient condensation cooling growth and annealing to obtain the crack-free large-size lanthanum bromide single crystal. The device and method can be used in the field of crystal growth.

The present invention relates to a bridgman-stockbarge method for preparing a cerium-doped lanthanum bromide scintillating crystal. According to the present invention, the modified bridgman-stockbarge method is adopted to prepare the scintillating crystal Cex:La(1-x)Br3; with the modified bridgman-stockbarge method, during the raw material melting stage, the upper temperature zone is divided into an upper temperature zone a and an upper temperature zone b through independent three temperature zone control, wherein the temperature of the upper temperature zone is higher than the melting point of the crystal, and the temperature of the upper temperature zone b is slightly higher than the temperature of the upper temperature zone a; during the spontaneous crystal nucleation stage, the embedded transparent quartz optical fiber is adopted to introduce helium neon laser, and the light loss change of the laser is observed to determine whether the single crystal of the spontaneously-nucleated seed crystal is formed after screening; after the crystal grows, the annealing treatment is performed for a long time under the reduction hydrogen atmosphere, the crystal thermal stress is eliminated, and the useless Ce<4+> in the crystal is subjected to valence variation to obtain the Ce<3+>.

The invention discloses an elemental analysis device combined with neutron-activation instant and delayed gamma rays, and belongs to the field of the application of nuclear technology. The elemental analysis device is used for measuring an inelastic scattered instant characteristic gamma energy spectrum of a sample in a combinational manner by using a fast neutron source and a lanthanum bromide detector, measuring a neutron captured instant characteristic gamma energy spectrum in the combinational manner by using a slow neutron source and a high-purity germanium detector and finally measuringa neutron-activation delayed characteristic gamma energy spectrum in the sample by using a sodium iodide detector. Relative to a conventional neutron-activation elemental analysis device, the elemental analysis device provided by the invention not only utilizes instant characteristic gamma rays generated by neutron activation, but also collects delayed characteristic gamma rays; relative to the instant rays, delayed rays have a small quantity, however, are not interfered by a neutron, and further, seldom has the superposition of characteristic peak positions of gamma rays; a specific element is conveniently and accurately analyzed and calculated. A fast neutron and a slow neutron irradiate the sample respectively to increase an irradiation time, and the generation efficiency and the collection efficiency of inelastic scattered gamma rays and neutron captured gamma rays are improved.

The invention discloses a method for measuring a neutron energy spectrum of a neutron radiation field by utilizing a lanthanum bromide detector. The method comprises the following steps: (1), establishing energy distribution function relationship (as shown in the description), generated by inelastic scattering of neutrons and a detector, of a neutron characteristic gamma energy peak net count andneutron energy, wherein phi(Ei) is neutron fluence of an ith energy group of a to-be-tested neutron energy spectrum; N<j>ngamma is a net count, generated by inelastic scattering of the neutrons and <79>Br, <81>Br and <139>La, of a jth characteristic gamma energy peak E<j>ngamma; epsilon<j>gamma is intrinsic full-energy peak detection efficiency, generated by the detector to the inner part, of thejth characteristic gamma energy peak E<j>ngamma; sigma<k>j(Ei) is a reaction cross section, generated by a reaction of neutrons with energy as Ei and kth nuclide, of the jth characteristic gamma energy peak; N<k>j is nuclear number for the kth nuclide and the neutrons to generate a jth reaction in a crystal; and Pji(Ei) is probability that the ith energy group neutrons participate in the jth reaction; (2), establishing j kinds of response equations for obtained j kinds of neutron characteristic gamma energy peak and forming an equation set; (3), determining response functions of the neutron characteristic gamma energy peak to different energy neutrons Ei; and (4), analyzing the equation set.

The invention relates to a lanthanum bromide crystal detector for detecting outer space gamma rays. The lanthanum bromide crystal detector is provided with a scintillating crystal and signal readout equipment thereof, wherein a packaging shell is arranged outside the scintillating crystal; glass is arranged on the light emergent surface of the packaging shell; the lanthanum bromide crystal detector is characterized in that the scintillating crystal is in a form of a lanthanum bromide crystal; a filling material is filled between the lanthanum bromide crystal and the packaging shell thereof; the filling material is composed of an elastic silicon optical coupling agent, magnesium oxide and titanium oxide according to the weight ratio of (4-6):(4-6):1; and the thickness of the filling material is 3-4 mm. According to the lanthanum bromide crystal detector disclosed by the invention, the disadvantage that the lanthanum bromide crystal detector in the prior art only can be used in a ground observation instrument can be overcome; the problems caused by fragile and deliquescent characteristics of the lanthanum bromide crystal can be well solved by adopting a packaging manner and an internal filling manner; and the gamma ray detector developed by the invention has the detection efficiency capable of reaching 137Cs4%@662KeV, can normally work in a spatial environment, and has a steady working performance.

The invention provides a fixed abrasive polishing pad and a dry polishing method for deliquescent crystal lanthanum bromide. The fixed abrasive polishing pad comprises a reactant, a catalyst, abrasive particles, a curing agent and a binding agent. According to the polishing method, the fixed abrasive polishing pad is used for polishing lanthanum bromide crystals and dry fixed abrasive polishing without liquid polishing media is adopted. The reactant and the lanthanum bromide crystals are subjected to a solid-phase chemical reaction under the action of the catalyst to generate a transition layer, the transition layer is removed under the mechanical action of the abrasive particles and the polishing pad, and a smooth surface can be obtained. The problems that the lanthanum bromide crystals can be easily dissolved in water and easily cracked after absorbing water in the polishing process are solved, the material utilization rate is high, the machining cost is low, the surface quality of the lanthanum bromide crystals is improved, chemical corrosion to polishing equipment by the liquid polishing media is avoided, and environmental pollution can be avoided.