Dynamics of N2 Dissociation upon Inner-Valence Ionization by Wavelength-Selected XUV Pulses.
Ionization of nitrogen by extreme ultraviolet (XUV) light from the Sun has recently been recognized as an important driver of chemical reactions in the atmosphere of Titan. XUV photons with energies of 24 eV and above convert inert nitrogen molecules into reactive neutral and ionic fragments that initiate chemical reactions. Understanding the XUV-induced fragmentation poses significant challenges to modern theory owing to its ultrafast time scales, complex electronic rearrangements, and strong dependence on the XUV photon energy. Here, we apply femtosecond time-resolved photoelectron and photoion spectroscopy to study dissociative ionization of nitrogen, the most abundant molecule in Titan's atmosphere, at selected XUV photon energies using a table-top XUV time-compensating monochromator. We probe the resulting dynamics using a time-delayed infrared (IR) ionization pulse. Coupled with ab initio calculations, the results allow us to assign the major dissociation channels resulting from production of an inner-valence hole, with important implications for models of Titan's XUV-driven atmospheric chemistry.
†Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
Martin
M
Eckstein
†Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
Chung-Hsin
CH
Yang
†Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
Markus
M
Kubin
‡National Research Council, Institute of Photonics and Nanotechnologies (CNR-IFN), via Trasea 7, I-35131 Padova, Italy.
Fabio
F
Frassetto
‡National Research Council, Institute of Photonics and Nanotechnologies (CNR-IFN), via Trasea 7, I-35131 Padova, Italy.
Luca
L
Poletto
†Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
Hans-Hermann
HH
Ritze
†Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
Marc J J
MJ
Vrakking
†Max-Born-Institute, Max-Born-Straße 2A, 12489 Berlin, Germany.
Oleg
O
Kornilov
DMRG; Titan atmosphere; Ultrafast dissociation; XUV monochromator; nitrogen