High-resolution photoelectron spectroscopy applied to free radicals
Wednesday october 22, 2 pm
ISMO Amphitheater
Investigating the photoionization of free radicals in the Vacuum-UltraViolet (VUV) spectral range is very important to obtain information on both the neutral species and their cations, for which the spectroscopic knowledge is very limited. Few groups among the world have tackled this subject since it represents two main challenges: (i) producing the radicals in the gas phase in a controlled and abundant way, and (ii) photoionizing them with a tunable VUV radiation with high-enough spectral resolution to assess the (ro)vibronic structure of their cations. Utilizing VUV photoelectron spectroscopy techniques both with VULCAIM setup (ISMO) and with the coincidence spectrometer of the DESIRS beamline (SOLEIL synchrotron), many free radicals have been studied. Instrumental advancements including upgrading the VUV laser system for medium-resolution operation and coupling the setup with the pyrolysis and electric discharge radical sources were carried out during my PhD on the VULCAIM setup at ISMO. SiH, CH3 and C6H5CH2 were studied via PFI-ZEKE spectroscopy at ISMO, while several silicon-bearing species were investigated using TPES method at SOLEIL. These new findings contribute to improve the thermochemical and spectroscopic databases, to benchmark ab initio calculations of these open shell species, and indirectly to support future astronomical observations as well as laboratory studies.