Dissociation dynamics of the water dication following one-photon double ionization. II. Experiment
Dissociation dynamics of the water dication following one-photon double ionization. II. Experiment
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DOI：
10.1103/physreva.98.053430
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发表时间：
2018-11-26
影响因子：
2.9
通讯作者：
Landers, A. L.
中科院分区：
文献类型：
--
作者：
Reedy, D.;Williams, J. B.;Landers, A. L.
我们证明了使用冷靶反冲离子动量谱进行状态选择性测量的解离通道以下单光子双电离的H2O。观察到的两个主要解离通道导致两体（OH+ + H+2 e（-））和三体（2 H（+）+ O +2 e（-））离子碎裂通道。在两体的情况下，我们观察到存在的自电离过程的双微分截面，这是类似的单光子双电离的氦远高于阈值。在三体情况下，结合Z。L. Streeter等人[Phys. Rev. A 98，053429（2018）]确定了八种填充的双金属状态及其相关的碎片几何结构。对于后者的情况下，国家特定的相对截面，中位动能释放，和渐近质子动量之间的中位角。这个基准水平的实验表明，在原则上，状态选择性固定框架的三重微分截面可以测量的水分子的一些dication状态。
We demonstrate the use of cold target recoil ion momentum spectroscopy to perform state-selective measurements of the dissociative channels following single-photon double-ionization of H2O. The two dominant dissociation channels observed lead to two-body (OH+ + H+ 2e(-)) and three-body (2H(+) + O + 2e(-)) ionic fragmentation channels. In the two-body case we observe the presence of an autoionization process with a double-differential cross section that is similar to the single-photon double-ionization of helium well above threshold. In the three-body case, momentum and energy correlation maps in conjunction with new classical trajectory calculations in the companion theory paper by Z. L. Streeter et al. [Phys. Rev. A 98, 053429 (2018)] lead to the determination of the eight populated dication states and their associated fragmentation geometry. For the latter case, state-specific relative cross sections, median kinetic energy releases, and median angles between asymptotic proton momenta are presented. This benchmark-level experiment demonstrates that, in principle, state-selective fixed-frame triple-differential cross sections can be measured for some dication states of the water molecule.