Fully Differential Cross Sections for Photo-Double-Ionization ofD2_

Abstract

We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double-ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis. This effect is reproduced by a model in which a pair of photoionization amplitudes is introduced for the light polarization parallel and perpendicular to the molecular axis.

Hydrogen and fluorine migration in photo-double-ionization of 1,1-difluoroethylene (1,1-C2H2F2Gaire1, Bocharova2, Sturm3 et al. 2014Phys. Rev. ASelf Cite41130View full textAdd to dashboardCite

“…This is due to a selection rule valid for dipole transitions based on parity conservation, and is well known in the PDI of atomic and diatomic systems with linear polarized light [3]. Already in the PDI of H 2 (D 2 ), this selection rule is somehow relaxed as the molecular axis breaks the spherical symmetry of the corresponding two-electron He case [3], and thus the nodal line of the atomic case collapses to a nodal point, which results in a less sharp zero in the relative angles of 180 • between the two electrons of H 2 molecule. Hence, it is not surprising that we observe counts near a back-to-back emission scenario in the double ionization of 1,1-C 2 H 2 F 2 .…”

“…In the indirect process (sometimes also referred to as a sequential process), photoejection of one electron leads to an intermediate cation state, which later decays by autoionization or other processes (e.g., Auger decay, fluorescence, etc.). After a couple of decades of studying the PDI of simple atoms and diatomic molecules (e.g., He, H 2 , N 2 , CO) in great detail [2][3][4][5][6][7][8][9][10], the investigation has been extended to polyatomic molecules in order to gain a general understanding of the double-ionization process in more complex systems. Simple hydrocarbon molecules are an ideal testbed for a series of studies with increasing complexity.…”

Single and triple differential cross sections for double photoionization ofH−

“…Recent experimental investigations have focused on double photoionization (DPI) of two-electron atoms [1][2][3][4][5][6][7] and molecules [8][9][10][11] as a sensitive probe of the correlated motion of electrons. The DPI problem is interesting from both experimental and theoretical viewpoints because the process by which an atom or molecule absorbs a photon of sufficient energy to eject two electrons into the continuum necessarily depends on electron correlation.…”

Molecular ionization and dissociation using synchrotron radiation and ultrashort laser pulses

“…Experiments in which both electrons are ejected from an oriented hydrogen molecule by absorption of a single photon are currently available [9,[71][72][73]. Among the latter, Weber et al [9,72] have recently demonstrated that the ejection pattern of the electrons depends sensitively on the bond distance between the two nuclei as they vibrate in their ground state.…”