Novel Near Field Detector for Three-Dimensional X-Ray Diffraction Microscopy

Abstract

Three dimensional X-ray diffraction (3DXRD) microscopy is a powerful technique that provides crystallographic and spatial information of a large number, of the order of thousands, of crystalline grains in a sample simultaneously. A key component of every 3DXRD microscopy experiment is the near field detector that provides high resolution spatial information of the grains. In this work we present a novel design for a semi-transparent, 16 megapixel near field detector. As opposed to a typical single scintillator phosphor detector, this design, we call the Quad Near Field Detector, uses four quadrants. It has a total field of view is 5.3 mm x 5.3 mm with an effective pixel size of 1.3 µm x 1.3 µm. The detector’s relatively large field of view can be used to obtain higher order diffraction spots which we anticipate will lead to improved spatial resolution in grain reconstructions. The large field of view can also enable the detector to be positioned further from the sample, in this way increasing the working distance and enabling larger environmental cells for in-situ studies. Many alignment parameters can be resolved by careful mechanical design. For this reason a novel translation stage for focusing the microscopes was developed, tested, and implemented. The near field detector was calibrated and characterized at the Cornell High Energy Synchrotron Source. The operational feasibility of such a multi-plate detector demonstrated in this work paves the way for new technologies in instrumentation of 3DXRD microscopy.