Schnorr K, Senftleben A, Kurka M, Rudenko A, Schmid G, Pfeifer T, Meyer K, Kübel M, Kling M F, Jiang Y H, Treusch R, Düsterer S, Siemer B, Wöstmann M, Zacharias H, Mitzner R, Zouros T J M, Ullrich J, Schröter C D, Moshammer R
Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany.
J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506, USA.
Phys Rev Lett. 2014 Aug 15;113(7):073001. doi: 10.1103/PhysRevLett.113.073001. Epub 2014 Aug 11.
The charge rearrangement in dissociating I_{2}^{n+} molecules is measured as a function of the internuclear distance R using extreme ultraviolet pulses delivered by the free-electron laser in Hamburg. Within an extreme ultraviolet pump-probe scheme, the first pulse initiates dissociation by multiply ionizing I_{2}, and the delayed probe pulse further ionizes one of the two fragments at a given time, thus triggering charge rearrangement at a well-defined R. The electron transfer between the fragments is monitored by analyzing the delay-dependent ion kinetic energies and charge states. The experimental results are in very good agreement with predictions of the classical over-the-barrier model demonstrating its validity in a thus far unexplored quasimolecular regime relevant for free-electron laser, plasma, and chemistry applications.
利用汉堡自由电子激光产生的极紫外脉冲，测量了离解的(I_{2}^{n +})分子中的电荷重排随核间距(R)的变化。在极紫外泵浦 - 探测方案中，第一个脉冲通过对(I_{2})进行多次电离来引发离解，而延迟的探测脉冲在给定时间进一步电离两个碎片之一，从而在明确的(R)处触发电荷重排。通过分析与延迟相关的离子动能和电荷态来监测碎片之间的电子转移。实验结果与经典的势垒模型预测非常吻合，证明了该模型在迄今为止尚未探索的与自由电子激光、等离子体和化学应用相关的准分子体系中的有效性。
