PHOTON SCIENCE

 Femtosecond X-ray free-electron lasers (FELs) provide unique opportunities for exploring ultra-fast dynamics in atoms and molecules and for imaging structure and dynamics of biological systems, complex materials, and matter under extreme conditions. Understanding the response of individual atoms and molecules to intense, ultrashort X-ray pulses is essential for most FEL applications in these fields.  Our work aims at providing this microscopic understanding by studying X-ray multiphoton ionization of atoms and molecules by means of electron, ion, and fluorescence spectroscopy using modern coincidence and covariance techniques as well as momentum-resolved electron and ion imaging. Recent examples include studies on high-Z atoms such as xenon and krypton, where we observed resonantly-enhanced X-ray multiphoton ionization [Rudek2012, Rudek_Dissertation,Rudek2013], as well as studies on small organic molecules with embedded high-Z atoms, where we traced ultrafast charge migration processes within the molecule [Erk2013PRL, Erk2013JPB, Erk_Dissertation]. The corresponding experiments are performed at the Free-Electron Laser Facilities LCLS at Stanford National Accelerator Laboratory in the USA and SACLA at SPring-8 in Japan.

Own References:

B. Erk, R. Boll, S. Trippel, D. Anielski, L. Foucar, B. Rudek, S.W. Epp, R. Coffee, S. Carron, S. Schorb, K.R. Ferguson, M. Swiggers, J.D. Bozek, M. Simon, T. Marchenko, J. Küpper, I. Schlichting, J. Ullrich, C. Bostedt, D. Rolles, and A. Rudenko, Imaging Charge Transfer in Iodomethane upon X-Ray Photoabsorption, Science 345, 288-291 (2014).

B. Rudek, S.-K. Son, L. M. Foucar, S. W. Epp, B. Erk, R. Hartmann, M. Adolph, R. Andritschke, A. Aquila, N. Berrah, C. Bostedt, J. Bozek, N. Coppola, F. Filsinger, H. Gorke, T. Gorkhover, H. Graafsma, L. Gumprecht, A. Hartmann, G. Hauser, S. Herrmann, H. Hirsemann, P. Holl, A. Hömke, L. Journel, C. Kaiser, N. Kimmel, F. Krasniqi, K.-U. Kühnel, M. Matysek, M. Messerschmidt, D. Miesner, T. Möller, R. Moshammer, K. Nagaya, B. Nilsson, G. Potdevin, D. Pietschner, C. Reich, D. Rupp, G. Schaller, I. Schlichting, C. Schmidt, F. Schopper, S. Schorb, C.-D. Schröter, J. Schulz, M. Simon, H. Soltau, L. Strüder, K. Ueda, G. Weidenspointner, R. Santra, J. Ullrich, A. Rudenko, and D. Rolles, Ultra-Efficient Ionization of Heavy Atoms by Intense X-Rays, Nature Photon. 6, 858 (2012). 

Benedikt Rudek, Multiple Ionization of Heavy Atoms by Intense X-Ray Free-Electron Laser Pulses, Dissertation, Universität Heidelberg (2012).

B. Rudek, D. Rolles, S.-K. Son, L. Foucar, B. Erk, S. Epp, R. Boll, D. Anielski, C. Bostedt, S. Schorb, R. Coffee, J. Bozek, S. Trippel, T. Marchenko, M. Simon, L. Christensen, S. De, S. Wada, K. Ueda, I. Schlichting, R. Santra, J. Ullrich, and A. Rudenko, Resonance-Enhanced Multiple Ionization of Krypton at an X-Ray Free-Electron Laser, Phys. Rev. A 87, 023413 (2013).

B. Erk,  D. Rolles,  L. Foucar, B. Rudek, S.W. Epp, M. Cryle, C. Bostedt, S. Schorb, J. Bozek, A. Rouzee^,, A. Hundertmark, T. Marchenko, M. Simon, F. Filsinger, L. Christensen, S. De, S. Trippel, J. Küpper, H. Stapelfeldt, S. Wada, K. Ueda, M. Swiggers, M. Messerschmidt, C.D. Schröter, R. Moshammer, I. Schlichting, J. Ullrich, and A. Rudenko, Ultrafast charge rearrangement and nuclear dynamics upon inner-shell multiple ionization of small polyatomic molecules, Phys. Rev. Lett. 110, 053003 (2013).

B. Erk, D. Rolles, L. Foucar, B. Rudek, S.W. Epp, M. Cryle, C. Bostedt, S. Schorb, J. Bozek, A. Rouzee, A. Hundertmark, T. Marchenko, M. Simon, F. Filsinger, L. Christensen, S. De, S. Trippel, J. Küpper, H. Stapelfeldt, S. Wada, K. Ueda, M. Swiggers, M. Messerschmidt, C.D. Schröter, R. Moshammer, I. Schlichting, J. Ullrich, and A. Rudenko, Inner-shell multiple ionization of polyatomic molecules with an intense X-ray Free-Electron Laser studied by coincident ion momentum imaging, J. Phys. B 46, 164031 (2013).

Benjamin Erk, Fragmentation Dynamics of Small Molecules upon Multiple Ionization by X-Ray Free-Electron Laser Pulses, Dissertation, Universität Heidelberg (2013).

H. Fukuzawa, S.-K. Son, K. Motomura, S. Mondal, K. Nagaya, S. Wada, X.-J. Liu, R. Feifel, T. Tachibana, Y. Ito, M. Kimura, T. Sakai, K. Matsunami, H. Hayashita, J. Kajikawa, P. Johnsson, M. Siano, E. Kukk, B. Rudek, B. Erk, L. Foucar, E. Robert, C. Miron, K. Tono, Y. Inubushi, T. Hatsui, M. Yabashi, M. Yao, R. Santra, and K. Ueda, Deep Inner-Shell Multiphoton Ionization by Intense X-Ray Free-Electron Laser Pulses, Phys. Rev. Lett. 110, 173005 (2013)

K. Motomura, H. Fukuzawa, S.-K. Son, S. Mondal, T. Tachibana, Y. Ito, M. Kimura, K. Nagaya, T. Sakai, K. Matsunami, S. Wada, H. Hayashita, J. Kajikawa, X.-J. Liu, R. Feifel, P. Johnsson, M. Siano, E. Kukk, B. Rudek, B. Erk, L. Foucar, E. Robert, C. Miron, K. Tono, Y. Inubushi, T. Hatsui, M. Yabashi, M. Yao, R. Santra, and K. Ueda, Sequential multiphoton multiple ionization of atomic argon and xenon irradiated by x-ray free-electron laser pulses from SACLA, J. Phys. B 46, 164024 (2013).

Press coverage on B. Erk et al., Imaging Charge Transfer in Iodomethane upon X-Ray Photoabsorption, Science 345, 288-291 (2014):

DESY press release: When is a molecule a molecule?

LCLS press release: X-ray laser measures leaping electrons


Press coverage on B. Rudek et al., Ultra-Efficient Ionization of Heavy Atoms by Intense X-Rays, Nature Photon. 6, 858 (2012):

Nature Photonics Author Interview: Stripping atoms, Nature Photonics 6, 874 (2012).

MPG press release: Xenon goes topless / Xenon oben ohne

DESY press release: 36 auf einen Streich – Forscher beobachten „unmögliche“ Ionisation / 36 in one fell swoop – researchers observe “impossible” ionization

SLAC press release: Study Provides Recipe for 'Supercharging' Atoms with X-ray Laser

spectroscopyNOW.com: Xenon warriors' success: Supercharged

Hamburger Abendblatt, 12.11.2012 : Forscher schießen mit Laser 36 Elektronen aus einem Atom