Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings

Article type: Research Article

Authors: Meiser, J.^a | Willner, M.^b | Schröter, T.^a | Hofmann, A.^c | Rieger, J.^d | Koch, F.^a | Birnbacher, L.^b | Schüttler, M.^{a; b} | Kunka, D.^a | Meyer, P.^a | Faisal, A.^a | Amberger, M.^a | Duttenhofer, T.^e | Weber, T.^d | Hipp, A.^{b; f} | Ehn, S.^b | Walter, M.^e | Herzen, J.^b | Schulz, J.^e | Pfeiffer, F.^b | Mohr, J.^{a; *}

Affiliations: [a] Institute of Microstructure Technology, Karlsruhe Institute of Technology Eggenstein-Leopoldshafen, Germany | [b] Department of Physics and Institute of Medical Engineering, Technische Universität München, Garching, Germany | [c] Institute for Applied Computer Science, Karlsruhe Institute of Technology, Karlsruhe, Germany | [d] Erlangen Center for Astroparticle Physics, Friedrich – Alexander – Universität Erlangen – Nürnberg, Erlangen, Germany | [e] Microworks GmbH, Karlsruhe, Germany | [f] Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany

Correspondence: [*] Corresponding author: Jürgen Mohr, Institute of Microstructure Technology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany. Tel.: + 49 721 608 244 33; Fax:+ 49 721 608 24331; E-mail: juergen.mohr@kit.edu

Abstract: Grating based X-ray differential phase contrast imaging (DPCI) allows for high contrast imaging of materials with similar absorption characteristics. In the last years’ publications, small animals or parts of the human body like breast, hand, joints or blood vessels have been studied. Larger objects could not be investigated due to the restricted field of view limited by the available grating area. In this paper, we report on a new stitching method to increase the grating area significantly: individual gratings are merged on a carrier substrate. Whereas the grating fabrication process is based on the LIGA technology (X-ray lithography and electroplating) different cutting and joining methods have been evaluated. First imaging results using a 2×2 stitched analyzer grating in a Talbot-Lau interferometer have been generated using a conventional polychromatic X-ray source. The image quality and analysis confirm the high potential of the stitching method to increase the field of view considerably.

Keywords: X-ray phase contrast imaging, talbot interferometry, field of view, grating, LIGA, stitching

DOI: 10.3233/XST-160552

Journal: Journal of X-Ray Science and Technology, vol. 24, no. 3, pp. 379-388, 2016