Time-resolved photoionization of cluster beams at the XUV free-electron laser FERMI

• Applicant: Professor Dr. Frank Stienkemeier
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2015 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 267447508

• Final Report Year: 2025

Final Report Abstract

Free-electron lasers (FEL) with wavelengths in the XUV or soft-X-ray range have opened up new possibilities to fundamentally understand molecular processes. With laser pulses in the femtosecond time range, they specifically enable real-time studies of the dynamics of processes following electronic excitation or ionization. We conducted femtosecond pumpprobe experiments with photoelectron, photoion, and fluorescence detection at the FEL FERMI in Trieste to investigate elementary processes and their dynamics in molecules and clusters. In ethanol and aminoethanol molecules, in addition to fragmentation behavior, the dynamics of processes after double ionization with XUV photons was studied, in particular, the roaming process leading to the formation of H 3+ was measured temporally. For measurements on ammonia clusters, we focused on the relaxation dynamics of solvated electrons. With the high FEL intensities available, a high degree of ionization and even the formation of nanoplasmas can be achieved, so another topic was to measure the formation and decay of plasma states in ammonia clusters. Several phases in the expansion of the plasma could be identified. Furthermore, helium clusters, representing atomic clusters with a simple electronic structure, were investigated. Here, the ultrafast localization of excitations, spin flips, and the formation of metastable states could be measured in real time. Moreover, in above-threshold ionization a drastic enhancement was measured and characterized in clusters compared to atoms. Finally, the project contributed to developments of experimental tools and collaborations on coherent diffraction imaging.

Publications

• Three-Dimensional Shapes of Spinning Helium Nanodroplets. Physical Review Letters, 121(25).
  Langbehn, Bruno; Sander, Katharina; Ovcharenko, Yevheniy; Peltz, Christian; Clark, Andrew; Coreno, Marcello; Cucini, Riccardo; Drabbels, Marcel; Finetti, Paola; Di Fraia, Michele; Giannessi, Luca; Grazioli, Cesare; Iablonskyi, Denys; LaForge, Aaron C.; Nishiyama, Toshiyuki; Oliver Álvarez de Lara, Verónica; Piseri, Paolo; Plekan, Oksana; Ueda, Kiyoshi ... & Möller, Thomas
  
• Deep neural networks for classifying complex features in diffraction images. Physical Review E, 99(6).
  Zimmermann, Julian; Langbehn, Bruno; Cucini, Riccardo; Di Fraia, Michele; Finetti, Paola; LaForge, Aaron C.; Nishiyama, Toshiyuki; Ovcharenko, Yevheniy; Piseri, Paolo; Plekan, Oksana; Prince, Kevin C.; Stienkemeier, Frank; Ueda, Kiyoshi; Callegari, Carlo; Möller, Thomas & Rupp, Daniela
  
• Real-Time Dynamics of the Formation of Hydrated Electrons upon Irradiation of Water Clusters with Extreme Ultraviolet Light. Physical Review Letters, 122(13).
  LaForge, A. C.; Michiels, R.; Bohlen, M.; Callegari, C.; Clark, A.; von Conta, A.; Coreno, M.; Di Fraia, M.; Drabbels, M.; Huppert, M.; Finetti, P.; Ma, J.; Mudrich, M.; Oliver, V.; Plekan, O.; Prince, K. C.; Shcherbinin, M.; Stranges, S.; Svoboda, V. ... & Stienkemeier, F.
  
• Real-time observation of water radiolysis and hydrated electron formation induced by extreme-ultraviolet pulses. Science Advances, 6(3).
  Svoboda, Vít; Michiels, Rupert; LaForge, Aaron C.; Med, Jakub; Stienkemeier, Frank; Slavíček, Petr & Wörner, Hans Jakob
  
• Time-resolved formation of excited atomic and molecular states in XUV-induced nanoplasmas in ammonia clusters. Physical Chemistry Chemical Physics, 22(15), 7828-7834.
  Michiels, Rupert; LaForge, Aaron C.; Bohlen, Matthias; Callegari, Carlo; Clark, Andrew; von Conta, Aaron; Coreno, Marcello; Di Fraia, Michele; Drabbels, Marcel; Finetti, Paola; Huppert, Martin; Oliver, Veronica; Plekan, Oksana; Prince, Kevin C.; Stranges, Stefano; Svoboda, Vít; Wörner, Hans Jakob & Stienkemeier, Frank
  
• Time-resolved quantum beats in the fluorescence of helium resonantly excited by XUV radiation. Journal of Physics B: Atomic, Molecular and Optical Physics, 53(24), 244012.
  LaForge, A. C.; Benediktovitch, A.; Sukharnikov, V.; Krušič, Š; Žitnik, M.; Debatin, M.; Falcone, R. W.; Asmussen, J. D.; Mudrich, M.; Michiels, R.; Stienkemeier, F.; Badano, L.; Callegari, C.; Di Fraia, M.; Ferianis, M.; Giannessi, L.; Plekan, O.; Prince, K. C.; Spezzani, C. ... & Berrah, N.
  
• Ultrafast relaxation of photoexcited superfluid He nanodroplets. Nature Communications, 11(1).
  Mudrich, M.; LaForge, A. C.; Ciavardini, A.; O.’Keeffe, P.; Callegari, C.; Coreno, M.; Demidovich, A.; Devetta, M.; Fraia, M. Di; Drabbels, M.; Finetti, P.; Gessner, O.; Grazioli, C.; Hernando, A.; Neumark, D. M.; Ovcharenko, Y.; Piseri, P.; Plekan, O.; Prince, K. C. ... & Stienkemeier, F.
  
• Enhancement of Above Threshold Ionization in Resonantly Excited Helium Nanodroplets. Physical Review Letters, 127(9).
  Michiels, R.; Abu-samha, M.; Madsen, L. B.; Binz, M.; Bangert, U.; Bruder, L.; Duim, R.; Wituschek, A.; LaForge, A. C.; Squibb, R. J.; Feifel, R.; Callegari, C.; Di Fraia, M.; Danailov, M.; Manfredda, M.; Plekan, O.; Prince, K. C.; Rebernik, P.; Zangrando, M. ... & Mudrich, M.
  
• Evolution and ion kinetics of a XUV-induced nanoplasma in ammonia clusters. Journal of Physics B: Atomic, Molecular and Optical Physics, 54(2), 024002.
  Michiels, R.; LaForge, A. C.; Bohlen, M.; Callegari, C.; Clark, A.; von Conta, A.; Coreno, M.; Di Fraia, M.; Drabbels, M.; Finetti, P.; Huppert, M.; Oliver, V.; Plekan, O.; Prince, K. C.; Stranges, S.; Wörner, H. J. & Stienkemeier, F.
  
• Diffraction imaging of light induced dynamics in xenon-doped helium nanodroplets. New Journal of Physics, 24(11), 113043.
  Langbehn, B.; Ovcharenko, Y.; Clark, A.; Coreno, M.; Cucini, R.; Demidovich, A.; Drabbels, M.; Finetti, P.; Di Fraia, M.; Giannessi, L.; Grazioli, C.; Iablonskyi, D.; LaForge, A. C.; Nishiyama, T.; Oliver Álvarez de Lara, V.; Peltz, C.; Piseri, P.; Plekan, O.; Sander, K. ... & Rupp, D.
  
• Relaxation dynamics in excited helium nanodroplets probed with high resolution, time-resolved photoelectron spectroscopy. Physical Chemistry Chemical Physics, 24(47), 28844-28852.
  LaForge, A. C.; Asmussen, J. D.; Bastian, B.; Bonanomi, M.; Callegari, C.; De, S.; Di Fraia, M.; Gorman, L.; Hartweg, S.; Krishnan, S. R.; Kling, M. F.; Mishra, D.; Mandal, S.; Ngai, A.; Pal, N.; Plekan, O.; Prince, K. C.; Rosenberger, P.; Aguirre Serrata, E. ... & Mudrich, M.
  
• Generation of interferometrically stable pulse pairs from a free-electron laser using a birefringent interferometer. Journal of Physics B: Atomic, Molecular and Optical Physics, 57(7), 075402.
  Ardini, B.; Richter, F.; Uboldi, L.; Cinquegrana, P.; Danailov, M.; Demidovich, A.; Ganeshamandiram, S. D.; Hartweg, S.; Kurdi, G.; Landmesser, F.; Michelbach, M.; Ngai, A.; Nikolov, I.; Rendler, N.; Stienkemeier, F.; Uhl, D.; Bruder, L.; Cerullo, G. & Manzoni, C.
  
• Method of kinetic energy reconstruction from time-of-flight mass spectra. Review of Scientific Instruments, 95(3).
  Ngai, A.; Dulitz, K.; Hartweg, S.; Franz, J. C.; Mudrich, M. & Stienkemeier, F.
  
• H2-roaming dynamics in the formation of H2+ following two-photon double ionization of ethanol and aminoethan. Scientific Reports, 15(1).
  Ngai, Aaron; Hartweg, Sebastian; Asmussen, Jakob D.; Bastian, Björn; Bonanomi, Matteo; Callegari, Carlo; Danailov, Miltcho; di Fraia, Michele; Feifel, Raimund; Ganeshamandiram, Sarang Dev; Krishnan, Sivarama; LaForge, Aaron; Landmesser, Friedemann; Ltaief, Ltaief Ben; Michelbach, Moritz; Pal, Nitish; Plekan, Oksana; Rendler, Nicolas; Raimondi, Lorenzo ... & Mudrich, Marcel