Development of an X-rag analytical microscope for the textural study of polycrystalling

岩石和矿物的纹理为研究地球和行星的自然历史提供了不可或缺的信息。本研究的目的是发展一种用于岩石和矿物研究的分析X射线显微镜。在项目实施期间，我们完成了以下课题。(1)A测角仪的设计和构造允许改变样品的取向，这是在分析X射线显微镜下通过X射线荧光、X射线衍射和Berg-Barret方法对样品的每个点进行分析所需的。(2)A利用新研制的测角仪和计算机控制系统，建立了一套新的特征X射线和X射线衍射束测绘系统。（3）研制了分析X射线显微镜，使其能在真空条件下有效地探测天然矿物主要组成元素Na等轻元素的特征X射线。（4）在新的X射线分析显微镜下观察了金刚石、石榴石、萤石等光学各向同性晶体及其它矿物如菱锰矿的内部结构。通过观察，我们成功地获得了关于内部结构成因的新信息，特别是关于孪晶金刚石和萤石的习性变化以及Trapiche结构的成因。（5）本文的结构观察结果表明，新的X射线分析显微镜在矿物和岩石成因研究中是有效的。

Textures on rocks and minerals provide indispensable information for the study of the natural history of earth and planets. The purpose of the present study is to develop an analytical X-ray microscope for the study of rocks and minerals. In the term of the project, we performed the following subjects. (1)A goniometer was designed and constructed to allow the change of the orientation of a specimen, which is required to carry out the analyses by X-ray fluorescence, X-ray diffraction and Berg-Barret methods for each point of a specimen under an analytical X-ray microscope. (2)A new system was constructed for mapping of characteristic X-rays and X-ray diffracted beams by using the newly developed goniometer and computer-control system. (3)The analytical X-ray microscope was developed for the usage under vacuum conditions to detect effectively the characteristic X-rays from light elements such as Na which are main constituent elements of natural minerals. (4)The internal textures of opticallyisotropic crystals of diamond, garnet and fluorite and some other minerals such as trapicheruby were observed under the new X-ray analytical microscope. Through the observation, we succeeded in obtaining new information about the genesis of the internal texture, especially for the habit change of twinned diamond and fluorite and the origin of the trapiche structure. (5)The present results of the textural observation indicate the validity of the new X-ray analytical microscope is useful to study of the genesis of minerals and rocks.