Amidst ongoing breakthroughs and technological innovations in global materials science, China's scientific instrument manufacturing industry is steadily rising to prominence. The TDF Series X-ray Crystal Analyzer, developed by Dandong Tongda Technology Co., Ltd., represents a leading example of domestically produced high-end analytical instrumentation. It is gaining traction in global scientific research and industrial sectors precisely due to its exceptional performance and reliable precision. The TDF Series X-ray Crystal Analyzer is a major analytical instrument designed for investigating the internal microstructure of substances. Its key applications encompass crystal orientation, defect inspection, lattice parameter determination, and residual stress measurement. Whether analyzing the structure of plates and rods, or deciphering the structure of unknown materials and single crystal dislocations, this equipment delivers accurate and reliable data support. In modern fields like materials science, semiconductor manufacturing, new energy development, and pharmaceuticals, a deep understanding of material microstructure has become the cornerstone of technological progress. The TDF Series is engineered for this purpose – empowering scientists and engineers worldwide to unlock the secrets of material properties. Vertical Tube Housing & Four-Port Design The TDF Series X-ray Crystal Analyzer incorporates a unique vertical tube housing design with four usable ports simultaneously. This innovative design significantly enhances operational efficiency, allowing users to switch rapidly between multiple experimental channels and save valuable research time. Precision Control with PLC Technology Equipped with an imported PLC control system, the TDF Series X-ray Crystal Analyzer demonstrates outstanding performance in control precision and anti-interference capabilities. This system not only enables precise control of high-voltage switching and lifting operations but also features an automatic X-ray tube training function, effectively extending the service life of both the X-ray tube and the entire instrument. For experimental scenarios requiring long-term, continuous operation, this reliability substantially reduces the risk of equipment failure and potential data loss. Powerful and Stable High-Voltage Generation System The high-voltage generator of the TDF Series performs exceptionally well, offering a tube voltage adjustable from 10 to 60 kV and a tube current range from 2 to 80 mA, with a rated output power of up to 5 kW. The stability of tube voltage and current reaches 0.3‰, ensuring highly reproducible experimental data. The system is also equipped with multiple protection functions (e.g., no voltage, overvoltage, no mA, over-power, no water, X-ray tube overtemperature), providing comprehensive safety assurance. Versatile X-Ray Tube Configurations To accommodate diverse analytical needs, the TDF Series offers a choice of various target materials, including Cu, Co, Fe, Cr, Mo, and W. With a rated power of 2.4 kW and focal spot options of point focus (1×1) and line focus (1×10), users can select the most suitable configuration based on sample characteristics and analytical objectives. Comprehensive Safety Protection Design Safety performance is another standout feature of the TDF Series X-ray Crystal Analyzer. Utilizing high-density, high-transparency lead glass for the X-ray protective shielding, the external radiation leakage is maintained at ≤ 0.1 μSv/h – a level well below international safety standards – ensuring reliable protection for operators. Configurations for Diverse Application Scenarios The TDF Series X-ray Crystal Analyzer supports various X-ray cameras, including Laue cameras (large/small powder), flat panel cameras, 3D sample stages, and Multiwire cameras (US-made). This flexible configuration scheme enables the instrument to adapt to a wide range of requirements, from fundamental research to high-end materials analysis. For applications demanding high-precision positioning, the TDF Series X-ray Crystal Analyzer offers a maximum positioning speed of up to 1500°/min, ensuring fast and accurate data acquisition. Whether for analyzing unknown materials in scientific research or for quality monitoring in industrial production, the TDF Series provides a dependable solution. As cutting-edge fields like new materials, new energy, and semiconductors continue to develop rapidly, the demand for material microstructure analysis is growing, and the required precision is constantly increasing. The TDF Series X-ray Crystal Analyzer will continue to evolve and upgrade to meet the latest needs of the global scientific and industrial communities. Dandong Tongda Technology Co., Ltd. remains committed to its philosophy of technological innovation and quality first. We will continue to provide global users with superior products and services, working hand-in-hand with scientists and engineers worldwide to jointly advance materials science and enhance industrial quality standards. We invite global partners and users to inquire and discuss collaboration opportunities. Discover more about the technical details and application cases of the TDF Series X-ray Crystal Analyzer. Let's join hands to explore the mysteries of the microscopic world of materials and jointly drive technological innovation and industrial progress!

The TD-5000 X-ray Single-Crystal Diffractometer is the outcome of a Major Scientific Instrument Development Project funded by China's Ministry of Science and Technology, with Dandong Tongda Science and Technology Co., Ltd. as the lead unit. This instrument represents a significant breakthrough for China in the high-end scientific instrument sector, filling a longstanding domestic gap in the development and manufacturing of single-crystal diffractometers. Its industry recognition is underscored by the prestigious "3i Award - 2022 Outstanding New Instrument of the Year," a highly authoritative accolade in the field.The TD-5000 X-ray Single-Crystal Diffractometer is capable of determining the three-dimensional spatial structure and electron density distribution of crystalline substances, including inorganic compounds, organic compounds, and metal complexes. It can analyze key crystal parameters such as bond lengths, bond angles, configuration, conformation, unit cell parameters, space group, and intermolecular interactions. The instrument is designed to determine the precise three-dimensional spatial structure of new compounds (in crystalline form)—including bond lengths, angles, configuration, conformation, and even bonding electron density—as well as the actual arrangement of molecules within the crystal lattice. It provides comprehensive structural information such as unit cell parameters, space group, molecular crystal structure, hydrogen bonding and weak intermolecular interactions, and molecular configuration and conformation.It is widely used in analytical research across various fields including chemical crystallography, molecular biology, pharmaceutical sciences, mineralogy, and materials science.The system is user-friendly, featuring one-click collection and a modular design. It employs high-precision goniometry with four-circle concentric technology to ensure goniometer center stability. Additionally, it is equipped with a high-performance detector and offers the option of a PILATUS hybrid pixel array detector, enabling high data quality and very fast scanning speeds. Beyond performance, the instrument is safe and reliable, featuring an electronic lead glass door interlock system that provides dual protection. The TD-5000 X-ray Single-Crystal Diffractometer is a precision analytical instrument designed for scientific research and high-end industrial applications. It excels in key performance metrics through sophisticated design and represents a significant breakthrough in its category. For users with relevant procurement needs who demand high-quality, high-standard instrumentation, it is a option worthy of serious consideration. Dandong Tongda Technology Co., Ltd. is committed to fully meeting your expectations with reliable performance and professional support. We look forward to your inquiries and potential collaboration.

The core function of the graphite curved crystal monochromator is to precisely filter out the desired Kα characteristic radiation from complex X-ray signals. This process is based on the Bragg diffraction principle, utilizing the precise arrangement and curved shape of the graphite crystal lattice to achieve selective transmission of X-rays. In practical applications, this component effectively eliminates interference from continuous X-rays, Kβ radiation, and fluorescent radiation generated by the sample itself. This filtering effect is particularly significant when analyzing samples containing elements such as manganese, iron, cobalt, and nickel using copper-target X-ray tubes. Dandong Tongda offers both graphite curved crystals and flat crystals. The use of graphite curved crystal monochromators can enhance the peak-to-background ratio, reduce background noise, improve the resolution of weak peaks, achieve a reflection efficiency of n ≥ 35%, and lower the diffraction angle of the diffractometer. The mosaic spread is ≤ 0.55°, and the crystal surface can be tilted by ±2°. These parameters ensure the stable performance of the instrument over long-term use. In X-ray analysis, the quality of data directly impacts the reliability of research conclusions. The graphite curved crystal monochromator significantly improves the quality of the collected signals by enhancing the peak-to-background ratio and reducing background noise. For diffractometer applications, this component also moderately lowers the diffraction angle, making weak peaks more distinct and improving the instrument's ability to resolve trace components. While this improvement may seem minor, it can play a critical role in key experiments. Application Value The graphite curved crystal monochromator demonstrates broad application value in environmental protection and electronics.It is suitable not only for fundamental research but also meets quality control and analytical needs in industrial production.By working in synergy with X-ray diffraction systems, this component provides reliable data support for materials science, chemical research, and industrial testing. ​ When used in conjunction with copper-target X-ray tubes, it effectively addresses analytical challenges for a variety of sample types.

Dandong Tongda's X-ray Crystal Analyzer adopts advanced X-ray diffraction technology, enabling non-destructive detection of microstructural information in various materials. Whether it's single crystal orientation, defect inspection, lattice parameter measurement, or residual stress analysis, this instrument provides accurate and reliable test data, offering solid support for material research and quality control. The instrument is equipped with a highly stable X-ray generator that delivers exceptional performance. The tube voltage can be precisely adjusted within the range of 10-60kV, and the tube current can be regulated from 2-60mA, with a stability of no more than ±0.005%. This ensures highly repeatable and accurate test results, providing researchers with dependable data assurance. Dandong Tongda's X-ray Crystal Analyzer integrates intelligent control and comprehensive safety protection. It features an imported PLC automatic control system, enabling unattended automatic timed measurements. The multi-level safety protection system includes no-pressure, no-current, over-voltage, over-current, over-power, no-water, and X-ray tube over-temperature protections, ensuring the safety of operators. The TDF series X-ray crystal analyzer adopts a vertical tube housing with four windows that can be used simultaneously. It utilizes imported PLC control technology, which offers high precision and strong anti-interference capabilities, ensuring the reliable operation of the system. The PLC controls the switching and adjustment of high voltage and includes an automatic training function for the X-ray tube, effectively extending the service life of both the X-ray tube and the instrument. The instrument's radiation protection enclosure is constructed with high-density, high-transparency leaded glass, with external radiation leakage far below national safety standards, allowing researchers to conduct experimental studies in a secure environment. As a national high-tech enterprise, Dandong Tongda Technology Co., Ltd. has a comprehensive quality management system and a technical R&D team. Its products not only meet domestic market demands but are also exported to numerous countries and regions, demonstrating the strength and capability of China's scientific instrument manufacturing. Dandong Tongda's X-ray Crystal Analyzer, with its outstanding performance and reliable quality, has become a powerful assistant in the field of material analysis. It helps researchers and engineers unveil the layers of the material world and explore more unknown possibilities.

The TD-5000 X-ray single crystal diffractometer is a high-performance analytical instrument developed and produced by Dandong Tongda Technology Co., Ltd. The following is a detailed introduction to the instrument: 1. Structure and technical characteristics of single crystal diffractometer (1) Core technical support Adopting the four circle concentric angle measuring instrument technology ensures that the center position of the angle measuring instrument remains constant during rotation, improving data integrity and accuracy. Equipped with a hybrid pixel detector, combined with single photon counting and hybrid pixel technology, it achieves low noise and high dynamic range data collection, suitable for challenging sample analysis. High power X-ray generator (3kW or 5kW), supporting the selection of Cu/Mo and other target materials, with a focal size of 1 × 1mm and a divergence of 0.5~1 mrad, meeting different experimental requirements. (2) Modularization and operational optimization The whole machine adopts PLC control technology and modular design to achieve plug and play of accessories, reducing the calibration process. The touch screen monitors the instrument status in real-time, and the one click acquisition system simplifies the operation process. The electronic lead door interlocking device provides dual protection, with X-ray leakage ≤ 0.12 µ Sv/h (at maximum power). 2. Technical parameters of single crystal diffractometer (1) Accuracy and repeatability 2 θ angle repeatability accuracy: 0.0001 ° Minimum step angle: 0.0001 ° Temperature control range: 100K~300K, control accuracy ± 0.3K. (2) Detector performance Sensitive area: 83.8 × 70.0 mm ² Pixel size: 172 × 172 μ m ², pixel spacing error<0.03% Maximum frame rate: 20 Hz, readout time of 7 ms, energy range of 3.5~18 keV. (3) Other key parameters X-ray tube voltage: 10~60 kV (1 kV/step), current 2~50 mA or 2~80 mA. Liquid nitrogen consumption: 1.1~2 L/hour (low-temperature experiment). 3. Application fields of single crystal diffractometer (1) Main research direction Crystal structure analysis: Analyze the atomic arrangement, bond length, bond angle, molecular configuration, and electron cloud density of single crystal materials. Drug crystallography: Study the crystal morphology of drug molecules, evaluate stability and biological activity. New material development: Analyze the three-dimensional structure of synthesized compounds to support material performance optimization. Nanomaterials and Phase Transition Research: Exploring the Characteristics of Nanocrystals and the Mechanism of Material Phase Transition. (2) Typical users School of Materials Science and Technology at Huazhong University of Science and Technology, Zhejiang University, University of Science and Technology of China, and other universities. Research institutions such as China Aerospace Science and Technology Corporation and China Shipbuilding Industry Corporation. 4. After sales service of single crystal diffractometer Provide original spare parts, home maintenance, remote diagnosis, and software upgrade services. Regular calibration services (in compliance with international standards) and providing users with operational and application training. 5. Accessories and extended functions for single crystal diffractometer (1) Optional attachments Multi layer film focusing lens (divergence of 0.5~1 mrad). Low temperature device (liquid nitrogen cooling). (2) Compatible devices It can be used in conjunction with X-ray fluorescence spectrometer (XRF), scanning electron microscope (SEM), etc. to achieve multi-scale material analysis. Overall, as a high-end single crystal diffractometer, the performance of TD-5000 has approached international standards, making it particularly suitable for universities, research institutes, and high-end material development needs. For more details, please refer to the official website of Dandong Tongda Technology Co., Ltd.

The X-ray crystal orienter is an indispensable instrument for precision machining and manufacturing of crystal devices. X-ray crystal orienter utilizes the principle of X-ray diffraction to accurately and quickly determine the cutting angle of natural and artificial single crystals (piezoelectric crystals, optical crystals, laser crystals, semiconductor crystals), and is equipped with a cutting machine for directional cutting of the above-mentioned crystals. The X-ray crystal orienter is widely used in the research, processing, and manufacturing industries of crystal materials. 1. Principle of X-ray crystal orienter: The X-ray crystal orienter utilizes the principle of X-ray diffraction to accurately and quickly determine the cutting angle of natural and artificial single crystals (piezoelectric crystals, optical crystals, laser crystals, semiconductor crystals). Equipped with a cutting machine, X-ray crystal orienter can be used for directional cutting of the above-mentioned crystals and is an indispensable instrument for precision machining and manufacturing of crystal devices. The X-ray crystal orientation instrument has a measurement accuracy of ± 30 inches, with a digital display mode and a smaller reading of 10 inches. Can measure samples with a diameter of 1-30 kilograms and 2-8 inches. Angle display: digital mode, measurement accuracy ± 30 inches. 2. Characteristics of X-ray crystal orienter: Easy to operate, no need for professional knowledge or proficient skills. The digital display angle is easy to observe and reduces reading errors. The monitor can be zeroed at any position for easy display of chip angle deviation values. The dual angle measuring instrument can work simultaneously, improving efficiency. The X-ray crystal orienter has a special integrator with peak amplification, which improves the detection accuracy. The integration of X-ray tube and high-voltage cable increases high-voltage reliability. The detector high-voltage adopts DC high-voltage module and vacuum suction sample board, which improves the angle measurement accuracy and speed. The main components of an X-ray crystal orienter are: Radiation tube: Typically, a copper target is used as the anode and grounded, while forced air cooling is employed for cooling. High voltage power supply: provides stable high voltage and current for X-ray tubes, and is one of the core components of the entire system. Detector: used to receive diffracted X-ray photons and convert them into electrical signals for subsequent processing and analysis. Goniometer: used to accurately measure the rotation angle of crystal samples, thereby determining the orientation information of the diffraction plane. Data processing system: processes, analyzes, and stores the signals output by the detector to obtain information about the crystal structure. 4. Application areas of X-ray crystal orienter: Materials Science: Used to study the crystal structures of various materials, including metals, ceramics, semiconductors, etc. Geology: Used for identifying mineral types, analyzing rock structures, etc. Chemistry: used to study the structure and changes of molecular crystals. Physics: used to explore the microstructure and physical properties of matter. In summary, with the continuous progress and innovation of science and technology,X-ray crystal orienter​ is believed that there will be more new materials and technologies applied in various fields in the future, promoting the continuous development of human society.

X-ray crystal analyzer operates on Bragg's law, measuring diffraction patterns to determine crystal structure. Key components include X-ray tube (2.4kW, multiple targets), spectroscopic crystal, detector, and goniometer. TDF series features 4-window operation, PLC control, and automated tube training. Widely used in materials science, chemistry, biology, and geology for structural analysis.

1. Function of single crystal diffractometer: The TD-5000 X-ray single crystal diffractometer is mainly used to determine the three-dimensional spatial structure and electron cloud density of crystalline substances such as inorganic, organic, and metal complexes, and to analyze the structure of special materials such as twinning, non commensurate crystals, quasicrystals, etc. Determine the accurate three-dimensional space (including bond length, bond angle, configuration, conformation, and even bonding electron density) of new compound (crystalline) molecules and the actual arrangement of molecules in the lattice; X-ray single crystal diffractometer can provide information on the crystal cell parameters, space group, crystal molecular structure, intermolecular hydrogen bonding and weak interactions, as well as structural information such as molecular configuration and conformation.X-ray single crystal diffractometer is widely used in analytical research in chemical crystallography, molecular biology, pharmacology, mineralogy, and materials science. The X-ray single crystal diffractometer is a high-tech product funded by the Ministry of Science and Technology of China's National Major Scientific Instrument and Equipment Development Project, led by Dandong Tongda Technology Co., Ltd., filling the gap in the development and production of single crystal diffractometers in China. 2. Characteristics of single crystal diffractometer: The whole machine adopts programmable logic controller (PLC) control technology; Easy to operate, one click collection system; Modular design, plug and play accessories, no need for calibration; Real time online monitoring through touch screen, displaying instrument status; High power X-ray generator with stable and reliable performance; Electronic lead door interlocking device, dual protection. 3. Accuracy of single crystal diffractometer: 2 θ angle repeatability accuracy: 0.0001 °; Minimum step angle: 0.0001 ° Temperature control range: 100K-300K; Control accuracy: ± 0.3K 4. Angle measuring instrument used in single crystal diffractometer: The use of four concentric circles technique ensures that the center of the angle measuring instrument remains unchanged regardless of any rotation, achieving the goal of obtaining the most accurate data and obtaining higher completeness. Four concentric circles are a necessary condition for conventional single crystal diffractometer scanning. 5. High speed two-dimensional detector used in X-ray single crystal diffractometer: The detector combines the key technologies of single photon counting and mixed pixel technology to achieve the best data quality while ensuring low power consumption and low cooling. It is applied in various fields such as synchrotron radiation and conventional laboratory light sources, effectively eliminating the interference of readout noise and dark current. The mixed pixel technology can directly detect X-rays, make the signal easier to distinguish, and efficiently provide high-quality data. 6. Low temperature equipment used in X-ray single crystal diffractometer: The data collected through low-temperature equipment yields more ideal results. With the help of low-temperature equipment, more advantageous conditions can be provided to enable undesirable crystals to obtain ideal results, as well as ideal crystals to obtain more ideal results. Temperature control range: 100K~300K; Control accuracy: ± 0.3K; Liquid nitrogen consumption: 1.1~2 liters/hour; 7. Optional accessory, multi-layer film focusing lens: X-ray tube power: 30W or 50W, etc; Divergence: 0.5~1 mrad; X-ray tube target material: Mo/Cu target; Focal spot: 0.5~2mm.

The graphite curved crystal monochromator used in X-ray diffractometers is a key component for selecting specific wavelengths of X-rays and removing unwanted radiation such as K β lines and fluorescent X-rays. The graphite curved crystal monochromator is a component installed in front of the X-ray detector, which monochromatizes the X-rays passing through the receiving slit and only detects the Kα characteristic X-rays in the X-ray spectrum. By using this device, continuous X-rays, K β characteristic X-rays, and fluorescent X-rays can be completely eliminated, enabling high signal-to-noise ratio X-ray diffraction analysis. When copper target X-ray tubes are used in conjunction with corresponding monochromators, fluorescent X-rays generated from Mn, Fe, Co, Ni based samples can be eliminated, making them suitable for analysis of various samples. working principle: Bragg diffraction: Based on Bragg's law, when X-rays are incident on a crystal at a certain angle, if 2dsin θ=n λ (where d is the interplanar spacing of the crystal, θis the incident angle, λ is the wavelength of the X-ray, and n is an integer), diffraction will occur. It utilizes this principle to adjust the orientation of the crystal so that only X-rays that meet specific conditions can pass through, thereby achieving the selection of X-ray wavelengths. Energy resolution: Due to the interplanar spacing and structural characteristics of graphite crystals, it can effectively distinguish X-rays of different energies. High energy resolution graphite curved crystal monochromator can further reduce unwanted radiation and improve the quality of diffraction data. Structural features: Curved shape: graphite curved crystal monochromator typically have a curved shape, which helps focus X-rays and improve diffraction efficiency. At the same time, the curved shape also helps to reduce the stress on the crystal, improve its stability and service life. High purity graphite: Graphite curved crystal monochromator is usually made of high-purity graphite materials to ensure their good diffraction performance and stability. High diffraction efficiency: It has a high diffraction efficiency, which can effectively select X-rays of the desired wavelength, thereby improving the quality of diffraction data. Wide wavelength range: It can operate over a wide wavelength range and is suitable for various types of X-ray diffraction experiments. Good stability: Due to the use of high-purity graphite material, it has good stability and a long service life. Application areas: Materials Science: In the field of materials science, X-ray diffractometers are widely used to study the crystal structure, phase composition, and other properties of materials. The graphite curved crystal monochromator, as an important component of X-ray diffractometer, provides important technical support for materials science research. Physics: In the field of physics, X-ray diffractometers are also used to study the microstructure and physical properties of matter. In summary, the graphite curved crystal monochromator used in X-ray diffractometers is an efficient and accurate X-ray selection and filtering device, providing important technical support for X-ray diffraction experiments.

The X-ray crystal orienter​ operates based on the principle of X-ray diffraction. The high voltage generated by the high-voltage transformer acts on the X-ray tube, producing X-rays. When the X-ray is irradiated onto the sample, diffraction occurs when the Bragg diffraction condition (n λ=2dsin θ) is satisfied. Among them, λ is the wavelength of X-rays, d is the spacing between atomic planes inside the crystal, and θ is the angle between the incident X-rays and the crystal plane. The diffraction line is received by the counting tube and displayed on the microampere meter of the amplifier. When using a monochromator, the diffraction line is monochromatized and then received by the counter and displayed on the microampere meter of the amplifier, thereby improving measurement accuracy. The X-ray crystal orienter can accurately and quickly determine the cutting angle of natural and artificial single crystals (piezoelectric crystals, optical crystals, laser crystals, semiconductor crystals), and is equipped with a cutting machine for directional cutting of the above-mentioned crystals. X-ray crystal orienter is an indispensable instrument for precision machining and manufacturing of crystal devices. The X-ray crystal orienter is widely used in the research, processing, and manufacturing industries of crystal materials. The X-ray crystal orienter is easy to operate, does not require professional knowledge or skilled techniques, displays the angle digitally, is easy to observe, and reduces reading errors. The display of the X-ray crystal orientation instrument can be zeroed at any position, making it easy to display the deviation value of the chip angle. The dual angle measuring instrument can work simultaneously, improving efficiency. The X-ray crystal orienter has a special integrator with peak amplification, which improves the detection accuracy. The integration of X-ray tube and high-voltage cable increases high-voltage reliability. The detector high-voltage adopts DC high-voltage module and vacuum suction sample board, which improves the angle measurement accuracy and speed. Overall, the X-ray crystal orienter is a precision instrument based on the principle of X-ray diffraction, which provides important technical support for crystal material research and related applications by accurately measuring the cutting angle of crystals.

The TDF series X-ray crystal analyzer is a large-scale analytical instrument and X-ray instrument used to study the internal microstructure of materials. It is mainly used for single crystal orientation, defect inspection, determination of lattice parameters, determination of residual stress, study of the structure of plates and rods, study of the structure of unknown substances, and single crystal dislocations.

The TD-5000 X-ray single crystal diffractometer is mainly used to determine the three-dimensional spatial structure and electron cloud density of crystalline substances such as inorganic, organic, and metal complexes, and to analyze the structure of special materials such as twinning, non commensurate crystals, quasicrystals, etc. Determine the accurate three-dimensional space (including bond length, bond angle, configuration, conformation, and even bonding electron density) of new compound (crystalline) molecules and the actual arrangement of molecules in the lattice; It can provide information on the crystal cell parameters, space group, crystal molecular structure, intermolecular hydrogen bonding and weak interactions, as well as structural information such as molecular configuration and conformation. X-ray single crystal diffractometer​ is widely used in analytical research in chemical crystallography, molecular biology, pharmacology, mineralogy, and materials science. Single crystal XRD is a high-tech product under the National Major Scientific Instrument and Equipment Development Project of the Ministry of Science and Technology, led by Dandong Tongda Technology Co., Ltd., filling the gap in the development and production of single crystal x-ray diffractometer in China.