J. Phys. IV France 09 (1999) Pr6-85-Pr6-88
Photo double-ionization of helium : A new approach combining R matrix and semiclassical techniques in an hyperspherical frameworkL. Malegat1, A. Kazansky2 and P. Selles1
1 Laboratoire de Spectroscopie Atomique et Ionique, Université Paris XI, 91405 Orsay, France
2 Institute of Physics, The University of St. Petersburg, St. Petersburg 198904, Russia
We introduce a new method for computing photo double ionization (PDI) cross sections for two electron atoms. It is formulated in terms of the hyperspherical radius R and relies upon a combination of R matrix techniques in the inner region R≤R0 with a semi classical approximation for the R motion in the outer region. We present a first application of this method to the PDI of He within a model of reduced dimensionality where r1=r2. It demonstrates the validity of our numerical scheme and provides a first quantitative estimate of the energy domain of validity of the Wannier mechanism.
© EDP Sciences 1999