• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of synchrotron radiation >Characterization of a bent Laue double-crystal beam-expanding monochromator
【24h】

Characterization of a bent Laue double-crystal beam-expanding monochromator

机译：弯曲拉金双晶束膨胀单色仪的表征

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A bent Laue double-crystal monochromator system has been designed for vertically expanding the X-ray beam at the Canadian Light Source's BioMedical Imaging and Therapy beamlines. Expansion by a factor of 12 has been achieved without deteriorating the transverse coherence of the beam, allowing phasebased imaging techniques to be performed with high flux and a large field of view. However, preliminary studies revealed a lack of uniformity in the beam, presumed to be caused by imperfect bending of the silicon crystal wafers used in the system. Results from finite-element analysis of the system predicted that the second crystal would be most severely affected and has been shown experimentally. It has been determined that the majority of the distortion occurs in the second crystal and is likely caused by an imperfection in the surface of the bending frame. Measurements were then taken to characterize the bending of the crystal using both mechanical and diffraction techniques. In particular, two techniques commonly used to map dislocations in crystal structures have been adapted to map local curvature of the bent crystals. One of these, a variation of Berg-Berrett topography, has been used to quantify the diffraction effects caused by the distortion of the crystal wafer. This technique produces a global mapping of the deviation of the diffraction angle relative to a perfect cylinder. This information is critical for improving bending and measuring tolerances of imperfections by correlating this mapping to areas of missing intensity in the beam.
机译：弯曲的LAUE双晶单色仪系统设计用于垂直地扩展加拿大光源的生物医学成像和治疗束线的X射线束。已经实现了12倍的扩展，而不会降低光束的横向相干性，允许通过高通量和大视场进行相位的成像技术。然而，初步研究揭示了梁中缺乏均匀性，推测由系统中使用的硅晶晶片的不完美弯曲引起。系统的有限元分析的结果预测，第二晶体将受到实验显示的最严重影响。已经确定大部分畸变在第二晶体中发生并且可能由弯曲框架表面的缺陷引起。然后采取测量来表征晶体的弯曲，使用机械和衍射技术。特别地，通常用于在晶体结构中映射脱位的两种技术已经适用于映射弯曲晶体的局部曲率。其中一个是Berg-Berrett地形的变型，用于量化由晶晶片的变形引起的衍射效果。该技术产生相对于完美圆柱的衍射角的偏差的全球映射。通过将该映射与光束中缺失强度的区域相关联，该信息对于提高缺陷和测量缺陷公差至关重要。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号