Attosecond Science Campaign
Realtime Observation of Ultrafast Electron Motion
This is the LCLS lead campaign in attosecond science. We will perform measurements of attosecond electron dynamics and subsequent coupling to nuclear motion using the soft X-ray attosecond capabilities of the LCLS. The continuous tunability and orders-of-magnitude pulse energy increase (compared to any previous attosecond source) produced by enhanced SASE operation at the LCLS enable a suite of nonlinear spectroscopies which are unavailable elsewhere. We attempt to make use of these unique capabilities to perform measurements demonstrating the control and observation of coherent electronic motion on its natural attosecond timescale, and explore how it affects the subsequent motion of the nuclei to drive chemical change. This campaign will provide pioneering insights into the coherent motion of electrons and how this drives chemical change, producing incisive X-ray observables against which theory can be directly tested on an unprecedented level of detail with particular emphasis on the atomic site-specific information content of X-ray transitions.
Campaign Team
LCLS Leadership James Cryan |
SLAC Zhaoheng Guo Argonne National Lab Gilles Doumy Lawrence Berkeley National Lab Oliver Gessner
Kansas State University Daniel Rolles | Imperial College, London Vitali Averbukh Universidad Autonoma de Madrid Gilbert Grell Paul Scherrer Institut Christoph Bostedt The Ohio State University Greg McCracken University of Connecticut Sandra Beauvarlet Lousianna State University Ken Lopata Ludwig-Maximilians Universitat Muchen Philipp Rosenberger Tohoku University Kiyoshi Ueda |
Research Results and Highlights
Notable results published as part of the Attosecond Campaign Collaboration.
Effect of the shot-to-shot variation on charge migration induced by sub-fs x-ray free-electron laser pulses
We demonstrated theoretically that the damping of the charge migration induced by 260 eV pulses in p-aminophenol due to the shot-to-shot variation of pulses generated by an XFEL is negligible in comparison to the natural damping due to the intrinsic fluctuation of the initial molecular geometry. This is an important result to validate our methodology for using attosecond XFELs to probe ultrafast charge motion.
Experimental demonstration of attosecond pump–probe spectroscopy with an X-ray free-electron laser
This study reports the first pump/probe experiment with sub-fs resolution with an x-ray free-electron laser. This method opens new research directions by allowing XFEL users to directly measure the motion of electrons on its natural temporal scale. The delay is benchmarked using the angular streaking technique. We present a first observation of femtosecond electron dynamics associated with the post collision interaction.
