The photodissociation dynamics of strong-field ionized methyl iodide (CH₃I) were probed using intense extreme ultraviolet (XUV) radiation produced by the SPring-8 Angstrom Compact free electron LAser (SACLA). Strong-field ionization and subsequent fragmentation of CH₃I was initiated by an intense femtosecond infrared (IR) pulse. The ensuing fragmentation and charge transfer processes following multiple ionization by the XUV pulse at a range of pump–probe delays were followed in a multi-mass ion velocity-map imaging (VMI) experiment. Simultaneous imaging of a wide range of resultant ions allowed for additional insight into the complex dynamics by elucidating correlations between the momenta of different fragment ions using time-resolved recoil-frame covariance imaging analysis. The comprehensive picture of the photodynamics that can be extracted provides promising evidence that the techniques described here could be applied to study ultrafast photochemistry in a range of molecular systems at high count rates using state-of-the-art advanced light sources.

中文翻译：

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时间分辨后坐力架协方差成像研究强磁场电离甲基碘中的多通道光解离和XUV诱导的电荷转移动力学

使用SPring-8埃奇紧凑型自由电子激光（SACLA）产生的强紫外线（XUV）探测了强电场电离的甲基碘（CH ₃ I）的光解离动力学。CH _3的强场电离和随后的裂解我是由强烈的飞秒红外（IR）脉冲启动的。在多质量离子速度图成像（VMI）实验中，通过XUV脉冲在一定的泵浦-探测延迟范围内进行多次电离之后，随之产生的碎片化和电荷转移过程随之而来。通过使用时间分辨的后坐力架协方差成像分析来阐明不同碎片离子的动量之间的相关性，对大量合成离子的同时成像可以进一步了解复杂的动力学。可以提取的光动力学综合图提供了有前途的证据，表明此处描述的技术可以应用在最先进的先进光源下，以高计数率研究一系列分子系统中的超快光化学。