We present results of classical Coulomb explosion simulations to demonstrate that Coulomb explosion imaging can serve as a robust method for differentiating molecular structures and following structural changes in pump-probe experiments by tracking the motion of individual atoms within the molecule.
Fundamental electron dynamics at the attosecond frontier and their direct coupling to structural dynamics of matter yield novel insights into the energy-distribution and protection mechanisms of Nature. The angular-streaking technique has exclusively demonstrated its capability of obtaining the full time-energy structure of XFEL pulses with attosecond resolution directly in the time-domain, thus enabling XFELs to study electron dynamics from element-specific vistas and their importance as onset of subsequent structural dynamics. We will present latest advances of this technique together with first results from the 2022 EuXFEL atto-campaign and the complementary prospects of the FLASH 2020+ innovation project at DESY.
N. Loh, Dmitri Starodub, Lukas Lomb, Christina Hampton, Andrew Martin, Raymond Sierra, Anton Barty, Andrew Aquila, Joachim Schulz, Jan Steinbrener, Robert Shoeman, Stephan Kassemeyer, Christoph Bostedt, John Bozek, Sascha Epp, Benjamin Erk, Robert Hartmann, Daniel Rolles, Artem Rudenko, Benedikt Rudek, Lutz Foucar, Nils Kimmel, Georg Weidenspointner, Günther Hauser, Peter Holl, Emanuele Pedersoli, MengNing Liang, Mark Hunter, Lars Gumprecht, Nicola Coppola, Cornelia Wunderer, Heinz Graafsman, Filipe R. N. Maia, Tomas Ekeberg, Max Hantke, Holger Fleckenstein, Helmut Hirsemann, Karol Nass, Thomas White, Herbert Tobias, George Farquar, W. Henry Benner, Stefan Hau-Riege, Christian Reich, Andreas Hartmann, Heike Soltau, Stefano Marchesini, Sasa Bajt, Miriam Barthelmess, Lothar Strueder, Joachim Ullrich, Philip Bucksbaum, Keith Hodgson, Mathias Frank, Ilme Schlichting, Henry Chapman, Michael Bogan
Profiling structured beams produced by X-ray free-electron lasers (FELs) is crucial to both maximizing signal intensity for weakly scattering targets and interpreting their scattering patterns. Earlier ablative imprint studies describe how to infer the X-ray beam profile from the damage that an attenuated beam inflicts on a substrate. However, the beams in-situ profile is not directly accessible with imprint studies because the damage profile could be different from the actual beam profile. On the other hand, although a Shack-Hartmann sensor is capable of in-situ profiling, its lenses may be quickly damaged at the intense focus of hard X-ray FEL beams. We describe a new approach that probes the in-situ morphology of the intense FEL focus. By studying the translations in diffraction patterns from an ensemble of randomly injected sub-micron latex spheres, we were able to determine the non-Gaussian nature of the intense FEL beam at the Linac Coherent Light Source (SLAC National Laboratory) near the FEL focus. We discuss an experimental application of such a beam-profiling technique, and the limitations we need to overcome before it can be widely applied.
Andrew Martin, Jakob Andreasson, Andrew Aquila, Saša Bajt, Thomas R. Barends, Miriam Barthelmess, Anton Barty, W. Henry Benner, Christoph Bostedt, John Bozek, Phillip Bucksbaum, Carl Caleman, Nicola Coppola, Daniel DePonte, Tomas Ekeberg, Sascha Epp, Benjamin Erk, George Farquar, Holger Fleckenstein, Lutz Foucar, Matthias Frank, Lars Gumprecht, Christina Hampton, Max Hantke, Andreas Hartmann, Elisabeth Hartmann, Robert Hartmann, Stephan Hau-Riege, Günther Hauser, Peter Holl, André Hoemke, Olof Jönsson, Stephan Kassemeyer, Nils Kimmel, Maya Kiskinova, Faton Krasniqi, Jacek Krzywinski, Mengning Liang, Ne-Te Duane Loh, Lukas Lomb, Filipe R. N. Maia, Stefano Marchesini, Marc Messerschmidt, Karol Nass, Duško Odic, Emanuele Pedersoli, Christian Reich, Daniel Rolles, Benedikt Rudek, Artem Rudenko, Carlo Schmidt, Joachim Schultz, M. Marvin Seibert, Robert Shoeman, Raymond Sierra, Heike Soltau, Dmitri Starodub, Jan Steinbrener, Francesco Stellato, Lothar Strüder, Martin Svenda, Herbert Tobias, Joachim Ullrich, Georg Weidenspointner, Daniel Westphal, Thomas White, Garth Williams, Janos Hajdu, Ilme Schlichting, Michael Bogan, Henry Chapman
Results of coherent diffractive imaging experiments performed with soft X-rays (1-2 keV) at the Linac Coherent
Light Source are presented. Both organic and inorganic nano-sized objects were injected into the XFEL beam
as an aerosol focused with an aerodynamic lens. The high intensity and femtosecond duration of X-ray pulses
produced by the Linac Coherent Light Source allow structural information to be recorded by X-ray diffraction
before the particle is destroyed. Images were formed by using iterative methods to phase single shot diffraction
patterns. Strategies for improving the reconstruction methods have been developed. This technique opens
up exciting opportunities for biological imaging, allowing structure determination without freezing, staining or
crystallization.
We rejort on the experimental realisation of time-resolved coincident Coulomb explosion imaging of H2-fragmentation
in 1014 W/cm2 laser fields. Combining a high-resolution 'reaction microscope' and a fs pump-probe setup, we map the
motion of wave packets dissociating via one- or two-photon channels, respectively, and observe two region of enhanced
ionization in accordance with earlier theoretical predictions. The long-term interferometric stability of our system
allows us to extend pump-probe experiments into the region of overlapping pulses, which offers new possibilities for
the manipulation of ultrafast molecular fragmentation dynamics.
We present results of high resolution fully differential measurements on single ionization of He, Ne, and Ar by 7-25 fs
linearly polarized 800nm laser pulses at intensities of up to 2.1015 W/cm2. Using a 'Reaction-Microscope' we were able
to trace signatures of multiphoton ionization deep into the tunnelling regime. Surprisingly, in the low-energy electron
spectra we observed several features (absence of the ponderomotive shifts, splitting of the peaks, their degeneration for
few-cycle laser pulses) typical for resonantly-enhanced ionization. Other remarkable features, as the sharp cusp-like
momentum distributions in the direction perpendicular to the laser field or the observed minima at zero longitudinal
momentum for He and Ne, can be reproduced by semiclassical models, where the electron motion in the combined laser
and Coulomb field is treated classically after the tunnelling.
Powerful laser radiation was applied to destroy capsides of viral particles in order to study the internal DNA organization. The significant results were obtained for bacteriophage Phi KZ. The possible mechanisms of capside destruction were considered.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.