Coulomb exploded directional double ionization of N₂O molecules in multicycle femtosecond laser pulses*

Abstract

We experimentally investigate Coulomb exploded directional double ionization of N2O molecules in elliptically polarized femtosecond laser pulses. The denitrogenation and deoxygenation channels are accessed via various pathways. It leads to distinct asymmetries in directional breaking of the doubly ionized N2O molecules versus the instantaneous laser field vector, which is revealed by tracing the sum-momentum spectra of the ionic fragments as a recoil of the ejected electrons. Our results demonstrate that the accessibility of the Coulomb exploded double ionization channels of N2O molecules are ruled by the detailed potential energy curves, and the directional emission of the fragments are governed by the joint effects of the electron localization-assisted enhanced ionization of the stretched molecules and the profiles of the molecular orbitals.

Ultrafast Coulomb explosion imaging of molecules and molecular clusters

“…For igniting a CE, multiple electrons are removed from molecule by absorbing enough amount of energy, either by charged particle (electron/ion) collision [58][59][60][61] or by photon (x-ray irradiation/intense laser). [17,47,[62][63][64][65][66][67][68][69][70][71][72][73][74] This process need to be fast enough for ensuring the nuclei within the molecular frame do not move. The system, in the quantum view, are populated in the high-lying repulsive potential energy surfaces of its cation after several electrons releasing, and the relative momenta of the charged fragments produced preserve the information of the initial structure of the molecular system when the axial recoil approximation [75][76][77] holds due to the ultrafast ionization of the system, as shown in Fig.…”