X-ray Diffraction Physics and Solid State

该提案由不同的章节组成， 不同的研究领域，其中X射线衍射用于 研究固体物理学的基本问题。 他们提出 进行硅的激光退火研究，并观察 在使用掠射熔化期间布拉格反射的消失 结合时间分辨计数的入射技术。 这项工作实际上正在进行中。 他们还希望确定 液相的径向分布函数，以及 观察到光致伸缩效应，晶格收缩， 激光照明由于高密度的电子-空穴对。 研究了蓝宝石中滑动电荷密度波（CDW）的形成机制 青铜晶体将使用穆斯堡尔衍射进行研究 法 实验研究了聚乙烯醇的性能 还提出了晶体氦。 的衍射研究 将进行固态He的电子密度， 和结构缺陷将通过白色 使用同步辐射束的束形貌。的项目 利用多重布拉格散射解决相位问题 衍射，由以前的NSF赠款支持，已经带来了 完成 因为它代表了一个重大突破， 衍射物理，完整的报告在一节中给出， 这个提议。

This proposal consists of different sections corresponding to different research areas in which x-ray diffraction is used to investigate basic problems of solid state physics. They propose perform a laser annealing study of silicon, and observe the disappearance of Bragg reflection during melting using a grazing incidence technique in conjunction with time resolved counting. This work is actually in progress. They also hope to determine the radial distribution function of the liquid phase, and to observe the photostriction effect, a lattice contraction during laser illumination due to high density of electron-hole pairs. The mechanisms of sliding Charge Density Waves (CDW's) in a blue bronze crystal will be investigated using a Mossbauer diffraction technique. An experimental investigation on the properties of crystalline Helium is also proposed. Diffraction studies of the electron density of He in the solid state will be carried out, and structural defects will be investigated by means of white beam topography using a synchrotron radiation beam. A project on use of multiple Bragg scattering for solving the phase problem in diffraction, supported by a previous NSF grant, has been brought to completion. Since it represents a major breakthrough in diffraction physics, a full report is given in one section of this proposal.