X射线衍射作为一种标准的物相结构分析技术，目前已被广泛应用于金属、聚合物、半导体、薄膜、镀膜材料等领域的物相结构检测。而随着自然科学的发展，对现有X射线衍射仪提出了新的需求。如对地学分析中的单颗粒矿物、大气单颗粒物等微米级样品进行分析时需要微米级X射线束，而现有常规衍射仪实现微米级分析时多以牺牲X射线强度为代价，这样大大降低了微区分析的效率。如何在不牺牲X射线束流强度的前提下同时实现毫米级和微米级区域的XRD（X-ray diffraction）分析。此外，在面对陨石、古瓷器和古铜器等样品时，由于样品十分珍贵并且其表面不平整或者有较大弯曲度，采用常规X射线衍射仪分析时，样品表面不平整会造成探测器计数降低以及衍射峰位漂移，从而影响物相分析的准确性，如何实现对形貌复杂样品无损且准确的XRD分析。同时，在分析古壁画中图案的颜料、古青铜中锈蚀产物等样品时，其分析区域尺寸大小不一并且晶体分布极不均匀。为确保照射区域内晶粒具有足够的随机定向性，并且不包含待测区域外的晶相信息，应根据待测区域尺寸调整照射到样品表面的X射线束斑尺寸实现对待测区域物相的完整分析。

基于以上限制X射线衍射仪发展的技术难题，本论文设计了一款点光源的自适应束斑X射线衍射仪，该衍射仪照射在样品表面的X射线束斑尺寸可随待测点尺寸变化。本文围绕自适应束斑X射线衍射仪的硬件和软件关键技术展开了研究。首先，高度集成的自动化运动控制系统是X射线衍射仪高效运转的基础。本论文采用PLC（Programmable Logic Controlle）为运动控制器，通过编写PLC运动控制程序实现对运动机构的集成式运动控制。该运动控制系统将X射线管运动轴、测角仪、样品调节台有机结合成六维联动运动轴，实现多维联动运动控制或独立运动控制。其次，通过结合毛细管微会聚X射线调控技术和CCD定位测量技术，开发了自适应束斑调节系统，该系统在毫米级常规区域和微米级微区范围内，可使照射点X射线束尺寸与待测点尺寸相匹配。此外，本衍射仪所采用的探测器包含单道分析功能和多道分析功能，因此本衍射仪在完成XRD信息测量的基础上还可以完成EDXRF（Energy Dispersive X-Ray Fluorescence）信息测量。在以上工作的基础上，本论文还为自适应束斑X射线衍射仪研发了一套专用的应用软件系统，该应用软件包含控制仪器功能和数据处理功能。

在完成自适应束斑X射线衍射仪的整体研发后，利用标准粉末和标准单晶对衍射仪的各项性能指标进行了表征，结果表明本衍射仪符合JJG 629-2014《多晶X射线衍射仪检定规程》的国家标准。

利用本论文研发的自适应束斑X射线衍射仪对文物样品和药品食品进行了分析。首先对西汉青铜器表面的腐蚀产物进行了分析，其主要的晶相为Cu₂(OH)₂CO₃、PbCO₃、CuCl和PbO₂等，这些晶相信息为保护青铜器以及理解青铜锈蚀机理提供了依据；接着对唐代三彩釉陶器真品和仿品进行分析，发现真品中晶相为3Al₂O₃·2SiO₂和一种SiO₂，而仿品中晶相为另一种SiO₂，晶相的差别可以为文物鉴定提供一定的参考；再对历代古琉璃建筑构件进行分析，发现明清时期琉璃胎体中主要为SiO₂，而宋元时期琉璃胎体中还含有Fe₂O₃晶相，宋代琉璃银釉中探测到PbO的晶相；对清代红绿彩瓷釉彩进行分析，测得绿釉主要晶相为Pb₈Cu(Si₂O₇)₃、红釉为Fe₂O₃、白釉为KAlSi₃O₈，根据釉彩的晶相信息可以为红绿彩瓷的低温复烧工艺提供一定的佐证；对吉州窑黑白彩绘瓷进行分析，发现白釉和黑釉中含量大量Fe元素，其中黑釉主要的呈色晶相为Fe₃O₄；最后对药品食品的物相信息进行了检测，牛黄解毒片中有效成分为雄黄As₂S₂，蒙脱石散中为蒙脱石MgO·Al₂O₃·5SiO₂·H₂O，麦丽素中主要是蔗糖C₁₂H₂₂O₁₁的晶相，实验结果有助于药品的真伪、有效成分以及食品的营养成分和品质鉴别。

本论文所研制的自适应束斑X射线衍射仪具有完全无损分析和对样品形貌不敏感的优势。此外还能同时实现微米级微区和毫米级常规区域的物相分析，以及可根据待测区域尺寸调节照射X射线束斑尺寸的能力。由此可见，自适应束斑X射线衍射仪在科技考古、药物科学、食品安全、材料科学、环境科学、工业应用等无损分析领域具有广泛的应用前景。

X-ray diffraction analysis is a standard analytical technique for measuring the phase structure of materials, which has been widely used in many fields, such as metals, polymers, ceramics, semiconductors, coated materials and so on. With the development of natural science, new demands are placed on existing X-ray diffractometers. In the field of geoscience, micron X-ray beam is prerequisite for the analysis of samples such as single mineral particle. However, the conventional diffractometer obtains microbeam at the expense of X-ray intensity, which greatly reduces the effectiveness of micro analysis. Therefore, how to achieve XRD analysis of conventional and microscopic regions with the same beam intensity is a problem to be solved. In the field of archaeometry, it is difficult to carry out nondestructive XRD analysis because the large and flat painted area can’t be found without sampling for most archaeological objects. As a result, it requires the diffractometer can achieve nondestructive XRD analysis. When analyzing the pigments in the ancient mural and the rust products in the ancient bronze, the size of detection point is different and the crystal phase distribution is very uneven. To ensure sufficient random orientation of the crystal and accuracy of measurement in the region to be tested, the diffractometer should adjust the X-ray spot according to the size of the measured area.

Based on these technical challenges that limit the development of X-ray diffractometers, this thesis designs an adaptive X-ray diffractometer with point source. The X-ray spot size of the diffractometer irradiated on the sample can be adapted to size of measured point. Study of the adaptive X-ray diffractometer in this paper mainly includes hardware and software key technologies. Firstly, a highly integrated automated motion control system is the basis for the efficient operation of the X-ray diffractometer, and this thesis uses a PLC as the controller for the motion mechanism, and writes a motion control program to achieve integrated motion control of the motion mechanism. The system combines the X-ray tube motion axis, the angle measuring instrument and the sample stage into a six-dimensional linkage motion axis to realize multi-dimensional linkage motion control or independent motion control. Secondly, the adaptive adjustment system of beam spot is developed by combining slightly-focusing ploycapillary X-ray control technology and CCD camera. The size of the X-ray irradiation point can be matched with the size of the point to be measured. In addition, the diffractometer also performs EDXRF spectroscopy. Based on the above work, a special application software system is developed for the adaptive X-ray diffractometer, which includes control instrument function and data processing function.

In this thesis, the adaptive X-ray diffractometer is used to analyze cultural relics, pharmaceuticals and foodstuffs. By studying the corrosion of bronze during the Western Han Dynasty, it is found that the Cu₂(OH)₂CO₃, PbCO₃, CuCl and PbO₂ are the main phases in corrosion products. The crystal phase of the corrosion provides the basis for protecting bronze and understanding the corrosion mechanism of bronze. Comparing the authentic and imitation of Tang Sancai, the crystal phases in the authentic are 3Al₂O₃·2SiO₂ and one kind of SiO₂, while the crystal phase in the imitation is another kind of SiO₂. The difference of crystal phase can provide some reference for the identification of cultural relics. The analysis of ancient colored glaze in the past dynasties reveals that the body in Ming and Qing Dynasty mainly consist of SiO₂, while the body in Song and Yuan Dynasty also contain Fe₂O₃ crystal phase. The PbO is detected in the silver glaze in Song Dynasty. Therefore, it is speculated that silver glaze is caused by the precipitation of PbO in long-term burial. Basing on the analysis of red and green porcelain fired in Qing Dynasty, it is found that the Pb₈Cu(Si₂O₇)₃, Fe₂O₃ and KAlSi₃O₈ are the main phases in the glazes. The crystal phase confirms the low-temperature reburning process of red and green porcelain fired in Qing Dynasty. The analysis of the black and white painted porcelain of the Jizhou kilns shows that the white and black glazes contain a large amount of elemental Fe and the main coloring crystal phase of the black glaze is Fe₃O₄. The experimental results show that the adaptive X-ray diffractometer can measure the effective crystal phase in pharmaceuticals and foodstuffs, which can help to detect the authenticity and active ingredients of pharmaceuticals as well as the nutritional composition and quality of foodstuffs.

The adaptive X-ray diffractometer developed in this thesis has the advantages of complete non-destructive analysis and insensitivity to the morphology of samples. In addition, phase analysis in both micron and millimeter scale areas can be realized simultaneously, and adjustment of the irradiated X-ray spot to the size of the area to be measured. This shows that the adaptive X-ray diffractometer has a wide range of applications, providing researchers with effective crystallographic information in fields such as scientific and technological archaeology, pharmaceutical science, food safety, materials science, environmental science and industrial applications.