Heidenreich Andreas, Last Isidore, Jortner Joshua
Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, D-12489, Berlin, Germany.
Phys Chem Chem Phys. 2009 Jan 7;11(1):111-24. doi: 10.1039/b819126n. Epub 2008 Nov 24.
Unique features of Coulomb explosion (CE) of many-electron elemental Xe(n) (n = 13-2171) clusters driven by ultraintense and ultrashort near-infrared laser pulses (peak intensities 10(15)-10(20) W cm(-2) and pulse lengths of 10-100 fs) manifest ion dynamics and energetics in the extreme, with ultrafast (5-15 A fs(-1)) velocities and ultrahigh (keV-1 MeV) energies. Relations were established between the CE attributes, obtained from molecular dynamics simulations and from electrostatic models, and the extreme cluster inner ionization levels (5-36 per ion), in conjunction with the laser parameters required for the attainment of complete outer ionization, which was approximated by cluster vertical ionization (CVI) initial conditions. Interrelationship between electron dynamics and nuclear dynamics stems from the effects of the laser pulse length on the energetics and from the characterization of the border radius for complete outer ionization. Our computational-theoretical analysis semi-quantitatively describes CE dynamics and energetics in the CVI limit and also the energetics in the presence of a persistent nanoplasma, which is in accord with experiment.
由超强超短近红外激光脉冲(峰值强度为10¹⁵ - 10²⁰ W cm⁻²,脉冲长度为10 - 100 fs)驱动的多电子元素Xe(n)(n = 13 - 2171)团簇的库仑爆炸(CE)具有独特特征,其展现了极端情况下的离子动力学和能量学,具有超快(5 - 15 Å fs⁻¹)速度和超高(keV - 1 MeV)能量。通过分子动力学模拟和静电模型获得的CE属性与极端团簇内部电离水平(每个离子5 - 36个)之间建立了关系,并结合了实现完全外层电离所需的激光参数,这通过团簇垂直电离(CVI)初始条件进行近似。电子动力学和核动力学之间的相互关系源于激光脉冲长度对能量学的影响以及完全外层电离边界半径的特征。我们的计算理论分析半定量地描述了CVI极限下的CE动力学和能量学,以及存在持久纳米等离子体时的能量学,这与实验结果相符。