论文标题
XUV诱导的氨簇中XUV诱导的纳米质量的进化和离子动力学
Evolution and ion kinetics of a XUV-induced nanoplasma in ammonia clusters
论文作者
论文摘要
来自自由电子激光器的高强度极端紫外线（XUV）脉冲可用于在簇中创建纳米质量。在参考[Michiels等。 PCCP，2020年； 22：7828-7834]我们研究了氨簇中XUV诱导的纳米肿瘤中激发态的形成。在本文中，我们通过对纳米肿瘤进化和离子动力学的详细分析扩展了先前的研究。我们使用延迟的紫外线激光作为探针，以在XUV诱导的等离子体中电离H $ _2^+$的激发态。采用协方差映射技术，我们表明质子的发射相关在等离子体动力学中起重要作用。测量由探针激光器产生的离子的时间依赖性动能，揭示了簇的电荷中和发生在亚皮秒时尺度上。此外，我们观察到从簇中弹出的RO振动激发的分子氢离子H $ _2^{+*} $。我们通过有限大小的非热等离子体的定性模型合理化数据。
High-intensity extreme ultraviolet (XUV) pulses from a free-electron laser can be used to create a nanoplasma in clusters. In Ref. [Michiels et al. PCCP, 2020; 22: 7828-7834] we investigated the formation of excited states in an XUV-induced nanoplasma in ammonia clusters. In the present article we expand our previous study with a detailed analysis of the nanoplasma evolution and ion kinetics. We use a time-delayed UV laser as probe to ionize excited states of H and H$_2^+$ in the XUV-induced plasma. Employing covariance mapping techniques, we show that the correlated emission of protons plays an important role in the plasma dynamics. The time-dependent kinetic energy of the ions created by the probe laser is measured, revealing the charge neutralization of the cluster happens on a sub-picosecond timescale. Furthermore, we observe ro-vibrationally excited molecular hydrogen ions H$_2^{+*}$ being ejected from the clusters. We rationalize our data through a qualitative model of a finite-size non-thermal plasma.
