An adaptive learning algorithm coupled with 3D momentum-based feedback is used to identify intense laser pulse shapes that control H$_3^+$ formation from ethane. Specifically, we controlled the ratio of D$_2$H$^+$ to D$_3^+$ produced from the D$_3$C-CH$_3$ isotopologue of ethane, which selects between trihydrogen cations formed from atoms on one or both sides of ethane. We are able to modify the D$_2$H$^+$:D$_3^+$ ratio by a factor of up to three. In addition, two-dimensional scans of linear chirp and third-order dispersion are conducted for a few fourth-order dispersion values while the D$_2$H$^+$ and D$_3^+$ production rates are monitored. The optimized pulse is observed to influence the yield, kinetic energy release, and angular distribution of the D$_2$H$^+$ ions while the D$_3^+$ ion dynamics remain relatively stable. We subsequently conducted COLTRIMS experiments on C$_2$D$_6$ to complement the velocity map imaging data obtained during the control experiments and measured the branching ratio of two-body double ionization. Two-body D$_3^+$ + C$_2$D$_3^+$ is the dominant final channel containing D$_3^+$ ions, although the three-body D + D$_3^+$ + C$_2$D$_2^+$ final state is also observed.

中文翻译：

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使用成形超快激光脉冲控制乙烷的 H$_3^+$ 形成

自适应学习算法与基于 3D 动量的反馈相结合，用于识别控制乙烷形成的 H$_3^+$ 的强激光脉冲形状。具体来说，我们控制了由乙烷的 D$_3$C-CH$_3$ 同位素产生的 D$_2$H$^+$ 与 D$_3^+$ 的比率，它在由一个原子形成的三氢阳离子之间进行选择或乙烷的两面。我们可以将 D$_2$H$^+$:D$_3^+$ 比率修改为最多三倍。此外，对几个四阶色散值进行线性啁啾和三阶色散的二维扫描，同时监测 D$_2$H$^+$ 和 D$_3^+$ 生产率。观察到优化的脉冲会影响 D$_2$H$^+$ 离子的产量、动能释放和角度分布，而 D$_3^+$ 离子动力学保持相对稳定。我们随后在 C$_2$D$_6$ 上进行了 COLTRIMS 实验，以补充在对照实验中获得的速度图成像数据，并测量了两体双电离的分支比。二体 D$_3^+$ + C$_2$D$_3^+$ 是包含 D$_3^+$ 离子的主要最终通道，尽管三体 D + D$_3^+$ + C$ _2$D$_2^+$ 也观察到最终状态。