Electron and nuclear dynamics of molecular clusters in ultraintense laser fields

2020-02-04 19:34:22

field inner electron dynamics ionization

责任者: Last, I.;Jortner, J. 单位: Sch. of Chem., Tel Aviv Univ., Israel 来源出处: Journal of Chemical Physics(J. Chem. Phys. (USA)),2004/01/15,120(3):1336-47 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 Xen,(D2)n, and (CD4)n (n=55-1061) in ultraintense (intensity I=1015-1019 W cm-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 R0) 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 ≲100 keV ions in the laser field was treated by molecular dynamics simulations, which incorporate electron-electron, electron-ion, ion-ion, and charge-laser interactions. High-energy electron dynamics also incorporates relativistic effects and includes magnetic field effects. We treat inner ionization considering inner field ignition, screening and fluctuation contributions as well as small [(⩽13%)] impact ionization contributions. Subsequent to inner ionization a charged nanoplasma is contained within the cluster, whose response to the composite (laser+inner) field results in outer ionization, which can be approximately described by an entire cluster barrier suppression ionization mechanism 关键词: molecular clusters;molecule-photon collisions;photoionisation;electron dynamics;nuclear dynamics;molecular clusters;ultraintense laser fields;extreme multielectron ionization;elemental clusters;semiclassical barrier suppression ionization mechanism;atomic species;molecular species;sequential-parallel inner-outer ionization;cluster inner ionization;laser field;inner fields;molecular dynamics simulations;electron-electron interactions;electron-ion interactions;ionion interactions;charge-laser interactions;high-energy electron dynamics;magnetic field effects;inner field ignition;screening;fluctuation contributions;small impact ionization contributions;inner ionization;charged nanoplasma;cluster barrier suppression ionization mechanism