Honnicke Marcelo Goncalves, Manica Juliana, Huang XianRong
Universidade Federal da Integracao Latino-Americana Foz do Iguacu Parana85867-970 Brazil.
Advanced Photon Source Argonne National Laboratory 9700 South Cass Avenue Argonne IL60439 USA.
J Appl Crystallogr. 2025 Apr 25;58(Pt 3):789-795. doi: 10.1107/S1600576725002985. eCollection 2025 Jun 1.
An analyzer-based X-ray phase contrast imaging experiment employing the forward-diffracted o-beam in a few-millimetre-thick Bragg-case asymmetrically cut analyzer crystal has been implemented and tested in a geometry similar to that used in conventional radiography. The high angular stability requirements were overcome using specially designed crystals and a closed-loop feedback intensity system, monitoring the intensity of the diffracted h-beam. Analyzer-based images (ABis) taken at different angular positions on the forward-diffracted o-beam rocking curve show different contrasts, as expected. However, the ABis did not show sharp borders. This was closely investigated by X-ray topography and Δ/ mapping and was attributed to the stresses caused by the analyzer crystal's own weight in the bulk. Further investigation of the crystal design using finite element analysis coupled with dynamical theory of X-ray diffraction is envisaged.
在一个几毫米厚的布拉格情况非对称切割分析晶体中，利用前向衍射的o光束进行了基于分析器的X射线相衬成像实验，并在与传统射线照相类似的几何结构中进行了测试。通过使用特殊设计的晶体和闭环反馈强度系统克服了高角度稳定性要求，该系统监测衍射h光束的强度。如预期的那样，在前向衍射o光束摇摆曲线上不同角度位置拍摄的基于分析器的图像（ABis）显示出不同的对比度。然而，ABis没有显示出清晰的边界。通过X射线形貌和Δ/映射对此进行了深入研究，并将其归因于分析晶体自身重量在主体中引起的应力。设想使用有限元分析结合X射线衍射动力学理论对晶体设计进行进一步研究。
