I. Extreme multielectron ionization.Electron and nuclear dynamics of molecular clusters in ultraintense laser fields

摘要

In this paper we present a theoretical and computational study of extreme multielectron ionization (involving the stripping of all the electrons from light, first-row atoms, and the production of heavily charged ions, e.g., Xe~(+q)(q<=36) from heavy atoms) in elemental and molecular clusters of Xe_n,(D_2)_n, and (CD_4)_n, (n = 55- 1061) in ultraintense (intensity I=10~(15)- 10~(19) Wcm~(-2)) laser fields. Single atom or molecule multielectron ionization can be adequately described by the semiclassical barrier suppression ionization (BSI) mechanism. Extreme cluster multielectron ionization is distinct from that of a single atomic or molecular species in terms of the mechanisms, the ionization level and the time scales for electron dynamics and for nuclear motion. The novel compound mechanism of cluster multielectron ionization, which applies when the cluster size (radius RG) considerably exceeds the barrier distance for the BSI of a single constituent, involves a sequential-parallel, inner-outer ionization. The cluster inner ionization driven by the BSI for the constituents is induced by a composite field consisting of the laser field and inner fields. The energetics and dynamics of the system consisting of high energy (<=3 keV) electrons and of