EFFECT OF INITIAL-STATE ORBITALS ON THE ANGULAR-CORRELATION PATTERN IN DOUBLE PHOTOIONIZATION

The neon 2p(4) S-1(e) triple differential cross section (TDCS) of phot oionization has been measured under equal energy sharing and displays two additional lobes compared with the related TDCS of helium. A model for the TDCS is derived which parameterizes the relative magnitudes a nd phases for the epsilon s epsilon p and epsilon p epsilon d continuu m channels in addition to an electron correlation factor and reproduce s the experimental data very well. This model traces the appearance of these additional lobes to the existence and interference of two conti nuum channels in the final state wavefunction. The present measurement serves as a test case for the more complicated treatment of energy- a nd angle-resolved double photoionization in rare gases other than heli um.