@misc{MayerLeverPicconietal.2022,
  author    = {Mayer, Dennis and Lever, Fabiano and Picconi, David and Metje, Jan and Ališauskas, Skirmantas and Calegari, Francesca and D{\"u}sterer, Stefan and Ehlert, Christopher and Feifel, Raimund and Niebuhr, Mario and Manschwetus, Bastian and Kuhlmann, Marion and Mazza, Tommaso and Robinson, Matthew Scott and Squibb, Richard James and Trabattoni, Andrea and Wallner, M{\aa}ns and Saalfrank, Peter and Wolf, Thomas J. A. and G{\"u}hr, Markus},
  title     = {Following excited-state chemical shifts in molecular ultrafast x-ray photoelectron spectroscopy},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1301},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-57744},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-577442},
  pages     = {9},
  year      = {2022},
  abstract  = {The conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The method allows us to discover that a major part of the population relaxes to the molecular ground state within 220-250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.},
  language  = {en}
}
@article{MayerLeverPicconietal.2022,
  author    = {Mayer, Dennis and Lever, Fabiano and Picconi, David and Metje, Jan and Ališauskas, Skirmantas and Calegari, Francesca and D{\"u}sterer, Stefan and Ehlert, Christopher and Feifel, Raimund and Niebuhr, Mario and Manschwetus, Bastian and Kuhlmann, Marion and Mazza, Tommaso and Robinson, Matthew Scott and Squibb, Richard James and Trabattoni, Andrea and Wallner, M{\aa}ns and Saalfrank, Peter and Wolf, Thomas J. A. and G{\"u}hr, Markus},
  title     = {Following excited-state chemical shifts in molecular ultrafast x-ray photoelectron spectroscopy},
  series = {Nature Communications},
  volume    = {13},
  journal   = {Nature Communications},
  publisher = {Springer Nature},
  address   = {Berlin},
  issn      = {2041-1723},
  doi       = {10.1038/s41467-021-27908-y},
  pages     = {9},
  year      = {2022},
  abstract  = {The conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The method allows us to discover that a major part of the population relaxes to the molecular ground state within 220-250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.},
  language  = {en}
}
@article{MetjeLeverMayeretal.2020,
  author    = {Metje, Jan and Lever, Fabiano and Mayer, Dennis and Squibb, Richard James and Robinson, Matthew Scott and Niebuhr, Mario and Feifel, Raimund and D{\"u}sterer, Stefan and G{\"u}hr, Markus},
  title     = {URSA-PQ},
  series = {Applied Sciences},
  volume    = {10},
  journal   = {Applied Sciences},
  number    = {21},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3417},
  doi       = {10.3390/app10217882},
  pages     = {13},
  year      = {2020},
  abstract  = {We present a highly flexible and portable instrument to perform pump-probe spectroscopy with an optical and an X-ray pulse in the gas phase. The so-called URSA-PQ (German for 'Ultraschnelle R{\"o}ntgenspektroskopie zur Abfrage der Photoenergiekonversion an Quantensystemen', Engl. 'ultrafast X-ray spectroscopy for probing photoenergy conversion in quantum systems') instrument is equipped with a magnetic bottle electron spectrometer (MBES) and tools to characterize the spatial and temporal overlap of optical and X-ray laser pulses. Its adherence to the CAMP instrument dimensions allows for a wide range of sample sources as well as other spectrometers to be included in the setup. We present the main design and technical features of the instrument. The MBES performance was evaluated using Kr M4,5NN Auger lines using backfilled Kr gas, with an energy resolution ΔE/E ≅ 1/40 in the integrating operative mode. The time resolution of the setup at FLASH 2 FL 24 has been characterized with the help of an experiment on 2-thiouracil that is inserted via the instruments' capillary oven. We find a time resolution of 190 fs using the molecular 2p photoline shift and attribute this to different origins in the UV-pump—the X-ray probe setup.},
  language  = {en}
}
@misc{MetjeLeverMayeretal.2020,
  author    = {Metje, Jan and Lever, Fabiano and Mayer, Dennis and Squibb, Richard James and Robinson, Matthew Scott and Niebuhr, Mario and Feifel, Raimund and D{\"u}sterer, Stefan and G{\"u}hr, Markus},
  title     = {URSA-PQ},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  number    = {1016},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-48307},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-483073},
  pages     = {15},
  year      = {2020},
  abstract  = {We present a highly flexible and portable instrument to perform pump-probe spectroscopy with an optical and an X-ray pulse in the gas phase. The so-called URSA-PQ (German for 'Ultraschnelle R{\"o}ntgenspektroskopie zur Abfrage der Photoenergiekonversion an Quantensystemen', Engl. 'ultrafast X-ray spectroscopy for probing photoenergy conversion in quantum systems') instrument is equipped with a magnetic bottle electron spectrometer (MBES) and tools to characterize the spatial and temporal overlap of optical and X-ray laser pulses. Its adherence to the CAMP instrument dimensions allows for a wide range of sample sources as well as other spectrometers to be included in the setup. We present the main design and technical features of the instrument. The MBES performance was evaluated using Kr M4,5NN Auger lines using backfilled Kr gas, with an energy resolution ΔE/E ≅ 1/40 in the integrating operative mode. The time resolution of the setup at FLASH 2 FL 24 has been characterized with the help of an experiment on 2-thiouracil that is inserted via the instruments' capillary oven. We find a time resolution of 190 fs using the molecular 2p photoline shift and attribute this to different origins in the UV-pump—the X-ray probe setup.},
  language  = {en}
}