DEVELOPMENT AND COMMISSIONING OF MICROBEAM CAPABILITIES ON BL12-2

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 正在为BL 12 -2开发和实施用于研究微晶的微束模式。 一个精密的显微衍射仪，内部开发，被用作基础仪器。 一个同轴摄像机被纳入光束线，用于沿光束轴沿着观察微晶，这减少了由于视差造成的未对准。 射束线设置还包括自动准直系统。为微束准直系统和同轴相机开发了软件工具。 实现了微束（15 μ m × 5 μ m）与phi轴的自动对准过程。 在Blu-Ice中实现了用于选择微束模式以及使用在线摄像机查看和居中样品的控件。 对基于衍射的晶体定心程序进行了修改，使其适用于微晶定心。 目前正在测试一种精确区分衍射和噪声的算法。 一个重要的努力继续旨在解决束稳定性的挑战，如完善的氦路径系统，温度控制系统，X射线束衰减器和反射镜间距反馈系统。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Microbeam mode for studying microcrystals is being developed and implemented for BL12-2. A precision microdiffractometer, developed in-house, is used as the base instrument. An in-line camera is incorporated into the beam line for viewing microcrystals along the beam axis, which reduces misalignments due to parallax. The beam line setup also includes an automated collimation system. Software tools were developed for the microbeam collimation system and the in-line camera. An automated alignment procedure of the microbeam (15 um x 5 um) to the phi axis was implemented. Controls for selecting the microbeam mode and viewing and centering samples with the in-line video camera were implemented in Blu-Ice. The diffraction based crystal centering routine was modified for centering microcrystals. An algorithm to accurately distinguish between diffraction and noise is currently being tested. A significant effort continues to be aimed at addressing beam stability challenges, such as refinement of a helium path system, temperature control system, x-ray beam attenuator and mirror pitch feedback system.