Ultrafast nuclear dynamics and non-uniform Coulomb explosion of heteroclusters

• Published in: Molecular physics 2005-07, Vol.103 (13), p.1735-1743
• Main Authors: Jortner, J., Last, I.
• Format: Article
• Language: English
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268970500096046

This paper reports on some unique features of the ion spatial distribution, energetics and time-resolved dynamics in Coulomb explosion of multicharged light-heavy heteroclusters, consisting of light, low-charge and heavy, high-charge, ions, e.g. hydroiodic acid  [image omitted] and its isotopic substituents  [image omitted] and  [image omitted]. In these clusters, extreme multielectron ionization in ultraintense laser fields (peak intensity I = 1015 - 1020 W cm-2) results in highly charged heavy ions, e.g. qI ≃ 7 at I = 6×1015 W cm-2 and qI = 25 at I = 1019 W cm-2. Molecular dynamics simulations based on the cluster vertical ionization (CVI) initial conditions, together with complete simulations involving both electron and nuclear dynamics of heteroclusters subjected to a Gaussian laser pulse, which were conducted for Coulomb explosion of  [image omitted] and  [image omitted] ionic clusters, reveal expanding, thin, two-dimensional spherical shells of the light D+ or H+ ions, with the monolayer expansion occurring on the femtosecond time scale. The expanding spherical nanoshells of light ions are analogous to a 'soap bubble', characterized by negative surface tension and driven by Coulomb pressure. The energetic data for the light ions reveal high energies with a narrow energy distribution, characterized by a lower energy cut-off, e.g. average energy Eav = 23 keV at width ΔE/Eav = 0.16, and a cut-off energy of EMIN = 19.2 keV for Coulomb explosion of  [image omitted] clusters. These dynamic, structural and energetic data for exploding multicharged light-heavy heteroclusters arise from kinematic overrun effects of the light ions.