Quasiresonance ionization of large multicharged clusters in a strong laserfield

The high-order multielectron ionization of Xe-531, Xe-1061, and Xe-2097 clu sters in a strong laser field is studied using classical dynamics. The simu lations are performed in the frozen geometry approximation for fixed ionic charges, so that only the evolution of the electrons, which are unbound to the ions, is examined. The dependence of the ionization efficiency on the l aser frequency and cluster radius is manifested by pronounced maxima. The p resence of these maxima favors the quasiresonance ionization mechanism, whi ch is related to the motion of the unbound electrons in the entire cluster. The high level of ionization (q similar to 8-18 per atom) is realized in t he expanded cluster, due to the Coulomb explosion. [S1050-2947(99)07408-9].