Interferences from fast electron emission in photoionization of H2 and H2+

J. FERNÁNDEZ, O. FOJÓN, A. PALACIOS AND F. MARTÍN

Freiburg, Germany

Conferencia; XXV International Conference on the Physics of Electronic and Atomic Collisions; 2007

    We present a theoretical study of fast electron emission produced in H2 and H2+ photoionization [1]. The bound and continuum molecular wave functions are obtained by means of B-spline techniques describing in a realistic way both the molecular structure and the long range behaviour of the charged fragments in the final channel of the reaction. [2, 3].     We show that, when the electron wave length is comparable to the molecular size, the electron angular distributions arising from fixed-in-space molecules exhibit pronounced interference patterns that critically depend on orientation and energy sharing between electronsand nuclei. In particular, for molecules oriented perpendicularly with respect to the photon polarization, typical Young’s double-slit interferences are observed. In the parallel orientation, the angular patterns reveal a complex nodal structure that may be understoodin terms of elementary models taking into account the angular dependence introduced by the photon polarization or alternativelyby confinement effects of the ionized electron (however, the predictive value of these models is limited as in the case of H2 one cannot relyon the reflection approximation). These patterns change dramatically as the molecule vibrates, which means that the motion of fast electronsstrongly depends on the nuclei’s position. All these conclusions should be of general validity for any diatomic molecule.    A signature of these interference effects may be detected also in the final reaction channel if a vibrational analysis is performed. As a matter of fact, unexpected non Franck-Condon transitions are observed in the case of H2 molecules in the population of the final vibrational states of the H2+ residual molecular ion. Details will be given during the Conference.References[1] J. Fernandez, O. A. Fojon, A. Palacios, and F. Martin Phys. Rev. Lett 98 (2007)  043005.[2] I. Sanchez, F. Martin, J. Phys. B: At. Mol. Opt. Phys. 30 (1997) 679.[3] F. Martin, J. Phys. B: At. Mol. Opt. Phys., 32 (1999) R197.