Abstract

Since their discovery by Roentgen in 1985, X-rays constitute an invaluable probe to study nature. The unique penetration power and short wavelength of X-rays allow us to develop microscopes capable of studying matter in a non-destructive manner in 2D and 3D at resolutions ranging from the micrometer scale down to the atomic scale. State-of-the-art X-ray microscopes benefit from X-ray sources that provide a high coherent flux, known as brilliance or brightness. In the last decades, brilliance has increased exponentially. Specifically, diffraction-limited storage rings, such as MAX IV, offer 10 to 100 times more brilliance than the previous generation sources. In parallel, the advent X-ray free-electron lasers with their laser-like X-rays and unprecedented short and intense pulses open new possibilities for X-ray imaging. This webinar will present the fundaments behind coherent X-ray imaging techniques that exploit the high-brilliance provided by X-ray free-electron lasers and diffraction-limited storage rings. For such purpose, we will introduce the fundaments of i) interactions of X-rays with matter, ii)  coherence, iii) brilliance and a brief history of its evolution, iii) coherent imaging, iv) near-field coherent imaging, v) far-field imaging, and vi) 3D imaging or tomography.

Biography

Pablo Villanueva started his scientific career as a PhD student in theoretical high energy physics. He did his PhD at the University of Valencia under the supervision of Prof. J. Bernabeu and F. Martinez-Vidal. His PhD offered him the opportunity to become a member of the BaBar collaboration at SLAC (USA). While working at SLAC, he attended several lectures about X-ray free-electron lasers (XFELs) and their applications. This new technology fascinated him so much that he decided to change his research field radically from theoretical high energy Physics to X-ray imaging after his PhD.

His first postdoc was in the TOMCAT group of Prof. Marco Stampanoni (X-ray tomography group) at the Paul Scherrer Institut (Switzerland). This postdoc offered him the opportunity to perform experiments and simulations using state-of-the-art X-ray imaging techniques. After three years at TOMCAT, he decided to start a second postdoctoral project at the Center for Free-electron laser science in DESY (Germany) in Prof. Henry Chapman's group.

Since March 2019, he has a tenure track position at the Division of Synchrotron Radiation Research, Physics Department, Lund University. His research aims to develop X-ray imaging methods at facilities like MAX IV and the European XFEL.