Journal Article

Laser-wakefield accelerators for high-resolution X-ray imaging of complex microstructures

Finlay, O., Smid, M., Falk, K., Lundh, O., Gerstmayr, E., Thomas, A. G. R., Ma, Y., Jaroszynski, D. A., Shahzad, M., Cipiccia, S., Bourgeois, N., Vieux, G., Willingale, L., Mangles, S. P. D., Streeter, M. J. V., Cole, J. M., Higginbotham, A., Senabulya, N., Kettle, B., Albert, F., Lopes, N. C., Wood, J. C., Hussein, A. E., Schlepütz, C. M., Lumsdon, C., Dann, S. J. D., Shahani, A. J., Lemos, N., Najmudin, Z., González, I. Gallardo, Rajeev, P. P., Krushelnick, K., Symes, D. R., Spesyvtsev, R.

2019

Overview

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 v ia 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  μ m 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.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/301/930/2735 / 639/766/1960/1137 / 639/766/930/2735 / Aluminum / Atom and Molecular Physics and Optics / Atom- och molekylfysik och optik (Här ingår: Kemisk fysik, kvantoptik) / Fysik / Humanities and Social Sciences / Imaging techniques / Lasers / Light sources / Medical imaging / Microscopes / multidisciplinary / Natural Sciences / Naturvetenskap / Oscillations / PARTICLE ACCELERATORS / Physical Sciences / PHYSICS OF ELEMENTARY PARTICLES AND FIELDS / Plasma-based accelerators / Science / Science (multidisciplinary) / Spatial discrimination / X-rays