Strong-field control of H3+ production from methanol dications: Selecting between local and extended formation mechanisms
Strong-field control of H3+ production from methanol dications: Selecting between local and extended formation mechanisms
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DOI：
10.1063/1.5129946
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发表时间：
2020-02-07
影响因子：
4.4
通讯作者：
Wells, E.
中科院分区：
文献类型：
--
作者：
Iwamoto, Naoki;Schwartz, Charles J.;Wells, E.
利用甲醇的CD 3OH同位素体，通过改变强飞秒激光脉冲的特性来控制D2 H+与D-3（+）形成的比率。D2 H+的检测表明涉及来自分子甲基侧的两个氢原子和来自羟基侧的质子的形成过程，而D-3（+）的检测表明仅涉及甲基的局部形成。这两种机制被认为涉及中性D-2部分。采用基于图像的反馈来指导学习算法的自适应控制策略导致D2 H +/D-3（+）比增强约2倍。优化的脉冲在主脉冲之后具有110-210 fs的二级结构，并且导致具有与从近变换限制脉冲产生的那些不同的动能释放分布的光致碎片。系统的线性啁啾和高阶色散项的激光脉冲的变化进行了比较，得到的结果与优化的脉冲形状。由AIP Publishing授权出版。
Using the CD3OH isotopologue of methanol, the ratio of D2H+ to D-3(+) formation is manipulated by changing the characteristics of the intense femtosecond laser pulse. Detection of D2H+ indicates a formation process involving two hydrogen atoms from the methyl side of the molecule and a proton from the hydroxyl side, while detection of D-3(+) indicates local formation involving only the methyl group. Both mechanisms are thought to involve a neutral D-2 moiety. An adaptive control strategy that employs image-based feedback to guide the learning algorithm results in an enhancement of the D2H+/D-3(+) ratio by a factor of approximately two. The optimized pulses have secondary structures 110-210 fs after the main pulse and result in photofragments that have different kinetic energy release distributions than those produced from near transform limited pulses. Systematic changes to the linear chirp and higher order dispersion terms of the laser pulse are compared to the results obtained with the optimized pulse shapes. Published under license by AIP Publishing.