Dissociative ATI of H2 and D2 in intense soft x-ray laser fields
Dissociative ATI of H2 and D2 in intense soft x-ray laser fields
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DOI：
10.1088/0953-4075/39/4/007
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发表时间：
2006-01
期刊：
影响因子：
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通讯作者：
K. Hoshina;A. Hishikawa;K. Kato;T. Sako;K. Yamanouchi;E. Takahashi;Y. Nabekawa;K. Midorikawa
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文献类型：
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作者：
K. Hoshina;A. Hishikawa;K. Kato;T. Sako;K. Yamanouchi;E. Takahashi;Y. Nabekawa;K. Midorikawa
首次通过飞行时间质谱法研究了 H2 和 D2 在强短脉冲软 X 射线场（λ = 29.6 nm，3 × 1012 W cm−2，15 fs）中的解离光电离过程，该场是钛蓝宝石激光器的 27 次高次谐波产生的。从 H2 中喷射出的 H+ 碎片离子分布在 3-20 eV 的动能范围内，峰值为 10.0 eV，产率对 27 次谐波的光场强度表现出 1.7(1) 量级的非线性依赖性。类似地，来自 D2 的 D+ 碎片离子分布在 3-20 eV 范围内，峰值为 10.3 eV，产率表现出 1.6 ± 0.2 量级的非线性依赖性。 H+和D+的动能分布及其产率的非线性可以通过两个共存的电离过程很好地解释：（i）单光子解离电离和（ii）主要进入排斥2pπu状态的解离双光子阈值以上电离（ATI）。
The dissociative photoionization processes of H2 and D2 in an intense, short-pulsed soft x-ray field (λ = 29.6 nm, 3 × 1012 W cm−2, 15 fs) generated as the 27th high-order harmonic of a Ti:sapphire laser is investigated for the first time by time-of-flight mass spectrometry. The ejected H+ fragment ions from H2 are distributed in the kinetic energy range of 3–20 eV peaked at 10.0 eV, and the yield exhibits a nonlinear dependence of the order of 1.7(1) on the light field intensity of the 27th harmonic. Similarly, the D+ fragment ions from D2 are distributed in the 3–20 eV range peaked at 10.3 eV, and the yield exhibits a nonlinear dependence of the order of 1.6 ± 0.2. The kinetic energy distributions of H+ and D+ and the nonlinearity in their yields are interpreted well by the two coexisting ionization processes: (i) one-photon dissociative ionization and (ii) dissociative two-photon above-threshold-ionization (ATI) mainly into the repulsive 2pπu state.