Pulse-duration dependence of the double-to-single ionization ratio of Ne by intense 780-nm and 800-nm laser fields: Comparison of simulations with experiments
Pulse-duration dependence of the double-to-single ionization ratio of Ne by intense 780-nm and 800-nm laser fields: Comparison of simulations with experiments
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DOI：
10.1103/physreva.99.043408
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发表时间：
2019-04
影响因子：
2.9
通讯作者：
Zhangjin Chen;Lina Zhang;Yali Wang;O. Zatsarinny;K. Bartschat;T. Morishita;C. Lin
中科院分区：
文献类型：
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作者：
Zhangjin Chen;Lina Zhang;Yali Wang;O. Zatsarinny;K. Bartschat;T. Morishita;C. Lin
由于目标的多电子性质，在强激光场中精确计算氖原子双电离与单电离的比率是很困难的。在这里，通过使用最先进的多电子 R 矩阵理论对 Ne+ 的电子碰撞电离和电子碰撞激发进行仔细评估，我们基于改进的定量再散射模型模拟了 780 和 800 nm 强激光场中 Ne2+ 的总双电离产率，脉冲持续时间在 7.5 至 200 fs 范围内。 Ne+ 相应的单电离产率是在 Perelomov、Popov 和 Terent'ev 的非绝热隧道模型中计算的。然后从计算的双电离和单电离产率获得氖双电离与单电离的比率。通过将比率归一化为通过求解短几个周期脉冲的时间相关薛定谔方程计算出的比率，我们将我们的结果与实验数据进行定量比较，以表明我们的模型很好地预测了实验结果。最后，我们分析了双电离比与单电离比的脉冲持续时间依赖性。
Accurate ab initio calculations of the ratio of double-to-single ionization of Ne atoms in strong laser fields are difficult due to the many-electron nature of the target. Here, with accurate total cross sections carefully evaluated by using the state-of-the-art many-electron R-matrix theory for both electron-impact ionization and electron-impact excitation of Ne+, we simulate the total double-ionization yields of Ne2+ in strong laser fields at 780 and 800 nm for pulse durations in the range from 7.5 to 200 fs based on the improved quantitative rescattering model. The corresponding single-ionization yields of Ne+ are calculated within the nonadiabatic tunneling model of Perelomov, Popov, and Terent'ev. The ratio of double-to-single ionization of Ne is then obtained from the calculated double- and single-ionization yields. By normalizing the ratio to the one calculated from solving the time-dependent Schrodinger equation for a short few-cycle pulse, we make quantitative comparisons of our results with experimental data to show that our model predicts the experimental findings very well. Finally, we analyze the pulse-duration dependence of the double-to-single ionization ratio.