Lithographically-fabricated channel arrays for confocal x-ray fluorescence microscopy and XAFS

17th Pan-American Synchrotron Radiation Instrumentation Conference

Woll, Arthur R.^1 ; Agyeman-Budu, David^2 ; Choudhury, Sanjukta^3 ; Coulthard, Ian^4 ; Finnefrock, Adam C.^5 ; Gordon, Robert^6 ; Hallin, Emil^4 ; Mass, Jennifer^7

Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY 14853, United States^1

Department of Materials Science, Cornell University, Ithaca, NY 14853, United States^2

Geol. Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada^3

Canadian Light Source, 44 Innovation Blvd, Saskatoon, SK S7N 2V3, Canada^4

Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486, United States^5

PNCSRF, APS, 9700 S. Cass Ave. 435E, Argonne, IL 60439, United States^6

Winterthur Museum, Winterthur, 19735, DE, United States^7

关键词: Advanced photon source;    Collection efficiency;    Cornell high-energy synchrotron sources;    Polycapillaries;    Spatial resolution;    Staggered arrays;    Working distances;    X-ray fluorescence microscopy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/493/1/012028/pdf
DOI  :  10.1088/1742-6596/493/1/012028

来源: IOP

【 摘 要 】

Confocal X-ray Fluorescence Microscopy (CXRF) employs overlapping focal regions of two x-ray optics - a condenser and collector - to directly probe a 3D volume. The minimum-achievable size of this probe volume is limited by the collector, for which polycapillaries are generally the optic of choice. Recently, we demonstrated an alternative collection optic for CXRF, consisting of an array of micron-scale collimating channels, etched in silicon, and arranged like spokes of a wheel directed towards a single source position. The optic, while successful, had a working distance of only 0.2 mm and exhibited relatively low total collection efficiency, limiting its practical application. Here, we describe a new design in which the collimating channels are formed by a staggered array of pillars whose side-walls taper away from the channel axis. This approach improves both collection efficiency and working distance, while maintaining excellent spatial resolution. We illustrate these improvements with confocal XRF data obtained at the Cornell High Energy Synchrotron Source (CHESS) and the Advanced Photon Source (APS) beamline 20-ID-B.