Coulomb explosion of diatomic molecules in intense XUV fields mapped by partial covariance
Coulomb explosion of diatomic molecules in intense XUV fields mapped by partial covariance
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DOI：
10.1088/0953-4075/46/16/164028
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发表时间：
2013-08-28
影响因子：
1.6
通讯作者：
Frasinski, L. J.
中科院分区：
文献类型：
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作者：
Kornilov, O.;Eckstein, M.;Frasinski, L. J.
在汉堡的自由电子激光器（FLASH）上记录了N-2和I-2分子库仑爆炸的单次发射飞行时间谱，并利用偏协方差映射技术进行了分析。偏协方差分析揭示了所有重要的库仑爆炸途径的详细情况，延伸到氮的N4+-N5+通道和碘的I8+-I9+通道。后一个通道的观察是出乎意料的，如果只考虑从基态离子的顺序电离过程。从每个解离通道的协方差图中提取的最大动能释放表明，氮分子的库仑爆炸比碘分子快得多。N-2电离动力学模型使用经典的轨迹模拟与实验结果吻合良好。结果表明，库仑爆炸的协方差映射可以用来测量自由电子激光的强度和脉宽。
Single-shot time-of-flight spectra for Coulomb explosion of N-2 and I-2 molecules have been recorded at the Free Electron LASer in Hamburg (FLASH) and have been analysed using a partial covariance mapping technique. The partial covariance analysis unravels a detailed picture of all significant Coulomb explosion pathways, extending up to the N4+-N5+ channel for nitrogen and up to the I8+-I9+ channel for iodine. The observation of the latter channel is unexpected if only sequential ionization processes from the ground state ions are considered. The maximum kinetic energy release extracted from the covariance maps for each dissociation channel shows that Coulomb explosion of nitrogen molecules proceeds much faster than that of the iodine. The N-2 ionization dynamics is modelled using classical trajectory simulations in good agreement with the outcome of the experiments. The results suggest that covariance mapping of the Coulomb explosion can be used to measure the intensity and pulse duration of free-electron lasers.