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- ItemMolecular Auger Interferometry(Bristol : IOP Publ., 2020) Khokhlova, M.; Cooper, B.; Ueda, K.; Prince, K.C.; Kolorenč, P.; Ivanov, M.; Averbukh, V.We propose a theory of interferometric measurement of a normal Auger decay width in molecules. Molecular Auger interferometry is based on the coherent phase control of Auger dynamics in a two-colour (ω/2ω) laser field. We show that, in contrast to atoms, in oriented molecules of certain point groups (e.g. CH3F) the relative ω/2ω phase modulates the total ionisation yield. A simple analytical formula is derived for the extraction of the widths of Auger-active states from a molecular Auger interferogram, avoiding the need of either attosecond or high-resolution spectroscopy.
- ItemCoulomb explosion of diatomic molecules in intense XUV fields mapped by partial covariance(Bristol : Institute of Physics Publishing, 2013) Kornilov, O.; Eckstein, M.; Rosenblatt, M.; Schulz, C.P.; Motomura, K.; Rouzée, A.; Klei, J.; Foucar, L.; Siano, M.; Lübcke, A.; Schapper, F.; Johnsson, P.; Holland, D.M.P.; Schlathölter, T.; Marchenko, T.; Düsterer, S.; Ueda, K.; Vrakking, M.J.J.; Frasinski, L.J.Single-shot time-of-flight spectra for Coulomb explosion of N2 and I2 molecules have been recorded at the Free Electron LASer in Hamburg (FLASH) and have been analysed using a partial covariance mapping technique. The partial covariance analysis unravels a detailed picture of all significant Coulomb explosion pathways, extending up to the N 4+-N5+ channel for nitrogen and up to the I 8+-I9+ channel for iodine. The observation of the latter channel is unexpected if only sequential ionization processes from the ground state ions are considered. The maximum kinetic energy release extracted from the covariance maps for each dissociation channel shows that Coulomb explosion of nitrogen molecules proceeds much faster than that of the iodine. The N 2 ionization dynamics is modelled using classical trajectory simulations in good agreement with the outcome of the experiments. The results suggest that covariance mapping of the Coulomb explosion can be used to measure the intensity and pulse duration of free-electron lasers.
- ItemInteratomic Coulombic Decay Processes after Multiple Valence Excitations in Ne Clusters(Bristol : IOP Publ., 2015) Iablonskyi, D.; Nagaya, K.; Fukuzawa, H.; Motomura, K.; Kumagai, Y.; Mondal, S.; Tachibana, T.; Takanashi, T.; Nishiyama, T.; Matsunami, K.; Johnsson, P.; Piseri, P.; Sansone, G.; Dubrouil, A.; Reduzzi, M.; Carpeggiani, P.; Vozzi, C.; Devetta, M.; Negro, M.; Faccialà, D.; Calegari, F.; Trabattoni, A.; Castrovilli, M.; Ovcharenko, Y.; Möller, T.; Mudrich, M.; Stienkemeier, F.; Coreno, M.; Alagia, M.; Schütte, B.; Berrah, N.; Callegari, C.; Plekan, O.; Finetti, P.; Spezzani, C.; Ferrari, E.; Allaria, E.; Penco, G.; Serpico, C.; De Ninno, G.; Diviacco, B.; Di Mitri, S.; Giannessi, L.; Prince, K..; Yao, M.; Ueda, K.We present a comprehensive analysis of autoionization processes in Ne clusters (~5000 atoms) after multiple valence excitations by free electron laser radiation. The evolution from 2-body interatomic Coulombic decay (ICD) to 3-body ICD is demonstrated when changing from surface to bulk Frenkel exciton excitation. Super Coster-Kronig type 2-body ICD is observed at Wannier exciton which quenches the main ICD channel.
- ItemDiffraction imaging of light induced dynamics in xenon-doped helium nanodroplets([London] : IOP, 2022-11-30) 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.; Ueda, K.; Fennel, T.; Prince, K.C.; Stienkemeier, F.; Callegari, C.; Möller, T.; Rupp, D.We explore the light induced dynamics in superfluid helium nanodroplets with wide-angle scattering in a pump–probe measurement scheme. The droplets are doped with xenon atoms to facilitate the ignition of a nanoplasma through irradiation with near-infrared laser pulses. After a variable time delay of up to 800 ps, we image the subsequent dynamics using intense extreme ultraviolet pulses from the FERMI free-electron laser. The recorded scattering images exhibit complex intensity fluctuations that are categorized based on their characteristic features. Systematic simulations of wide-angle diffraction patterns are performed, which can qualitatively explain the observed features by employing model shapes with both randomly distributed as well as structured, symmetric distortions. This points to a connection between the dynamics and the positions of the dopants in the droplets. In particular, the structured fluctuations might be governed by an underlying array of quantized vortices in the superfluid droplet as has been observed in previous small-angle diffraction experiments. Our results provide a basis for further investigations of dopant–droplet interactions and associated heating mechanisms.