Laser-wakefield accelerators (LWFAs) are high acceleration-gradient plasma-based particle accelerators capable of producing ultra-relativistic electron beams. Within the strong focusing fields of the wakefield, accelerated electrons undergo betatron oscillations, emitting a bright pulse of X-rays with a micrometer-scale source size that may be used for imaging applications. Non-destructive X-ray phase contrast imaging and tomography of heterogeneous materials can provide insight into their processing, structure, and performance. To demonstrate the imaging capability of X-rays from an LWFA we have examined an irregular eutectic in the aluminum-silicon (Al-Si) system. The lamellar spacing of the Al-Si eutectic microstructure is on the order of a few micrometers, thus requiring high spatial resolution. We present comparisons between the sharpness and spatial resolution in phase contrast images of this eutectic alloy obtained via X-ray phase contrast imaging at the Swiss Light Source (SLS) synchrotron and X-ray projection microscopy via an LWFA source. An upper bound on the resolving power of 2.7 ± 0.3 μm of the LWFA source in this experiment was measured. These results indicate that betatron X-rays from laser wakefield acceleration can provide an alternative to conventional synchrotron sources for high resolution imaging of eutectics and, more broadly, complex microstructures. © 2019, The Author(s).
Export Date: 14 March 2019
Correspondence Address: Hussein, A.E.; Center for Ultrafast Optical Science, University of MichiganUnited States; email: aehuss@umich.edu
Funding details: Engineering and Physical Sciences Research Council, 312453, EP/J018171/1, EP/N028694/1, EP/J500094/1
Funding details: Fuel Cell Technologies Program, FCT
Funding details: Lawrence Livermore National Laboratory
Funding details: European Commission, 654148
Funding details: Ministério da Ciência, Tecnologia e Ensino Superior, MCTES, POCI/FIS/59574/2004
Funding details: Fundação para a Ciência e a Tecnologia
Funding details: ST/P002056/1
Funding details: Natural Sciences and Engineering Research Council of Canada
Funding details: Cockcroft Institute, ST/P000835/1
Funding details: 653782
Funding details: U.S. Department of Energy
Funding details: Lawrence Livermore National Laboratory, DE-AC52-07NA27344
Funding text 1: We acknowledge support of the UK STFC core grants ST/P002056/1 (Cockcroft Institute), ST/P000835/1 (John Adams Institute), and the United States Department of Energy Grant No. DE-NA0002372. This work was partially supported by EuPRAXIA (Grant No. 653782), EC’s LASERLAB-EUROPE (Grant No. 654148), UK EPSRC Grant No. EP/J018171/1, EP/J500094/1 and EP/N028694/1), EuCARD-2 (Grant No. 312453), the Extreme Light Infrastructure (ELI) European Project, National Science and Engineering Research Council of Canada, and by FCT - Fundação para a Ciência e a Tecnologia, Ministério da Ciência e Ensino Superior, Portugal under the contract POCI/FIS/59574/2004 and by the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under the contract DE-AC52-07NA27344, as well as Lawrence Livermore National Security, LLC, and DOE Early Career Research Prog. SCW1575/1. LLNL-JRNL-742178. We acknowledge the Paul Scherrer Institut, Villigen, Switzerland for provision of synchrotron radiation beamtime at the TOMCAT beamline X02DA of the SLS and would like to thank Julie Fife for assistance. The authors also thank the staff at the Central Laser Facility, Rutherford Appleton Laboratory for their assistance.
