A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

Abstract

Articles you may be interested inWe present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10 −1 mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

Charge migration and charge transfer in molecular systems

“…Within the NCCR-MUST, a source of high-harmonic generation (HHG) vacuum-ultraviolet (HHG) radiation was built and coupled to a chamber for the ultrafast PES of solutions 168–170 . An ideal model system for intramolecular charge transfer is the ferric [Fe III (CN) 6 ] 3− whose absorption in the 400 nm region is due to a ligand-to-metal charge transfer state, and therefore its excitation leads to a reduction of the Fe centre.…”

Charge transfer to solvent dynamics in iodide aqueous solution studied at ionization threshold

“…Inprovements of this technique resulted in the first photoelectron spectra from liquid water and several alcohols [101,102]. Today, many groups world-wide use the liquid microjet technique successfully for, e.g., PE spectroscopy or soft X-ray emission spectroscopy [103,104,43,69,105,106].…”

Grating Configurations for the Spectral Selection of Coherent Ultrashort Pulses in the Extreme-Ultraviolet

“…As a test case, the design of a monochromator to be used for the spectral selection of HHs that has been developed in the framework of a collaboration between CNR-IFN Padova (Italy) and the Laboratory of Ultrafast Spectroscopy of the École Politechnique Fé dé rale de Lausanne (LSU-EPFL, Switzerland) to be used for time-resolved photoelectron spectroscopy from liquid samples [26] is reported here. The instrumental parameters are summarized in Table 1.…”