Time-dependent formalism of double ionization of multielectron atomic targets

A time-dependent formalism for treating double ionization of atomic targets with core electrons is presented. It relies on the solution of the time-dependent Schrodinger equation with a combined orbital and grid-based representation of the time-evolving wave packet. Total and differential double ionization probabilities and cross sections are then obtained through a exterior complex scaling implementation. The method is demonstrated for single-photon double ionization of the valence electrons of beryllium atom using 500 attosecond pulsed lasers, with the inner-shell electrons held fixed in the frozen-core orbitals. The extracted cross sections are compared to existing experimental and time-independent theoretical results. The accuracy of the formalism is demonstrated in furtherance of investigation of physical processes induced by ultrashort pulses in multielectron atoms that cannot be achieved in a time-independent framework. (c) 2012 Elsevier B.V. All rights reserved.