Molecular frame photoelectron angular distributions in dissociative photoionization of H2 in the region of the Q1 and Q2 doubly excited states
Molecular frame photoelectron angular distributions in dissociative photoionization of H2 in the region of the Q1 and Q2 doubly excited states
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Q1 和 Q2 双激发态区域 H2 解离光电离的分子架光电子角分布
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
D. Dowek
中科院分区：
文献类型：
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作者：
A. Lafosse;M. Lebech;J. Brenot;P. Guyon;L. Spielberger;O. Jagutzki;J. Houver;D. Dowek
用(VH+，Ve，P)矢量相关方法研究了真空紫外线偏振同步辐射P诱导的H2的离解光电离.三个光子激发能hν=2 0、2 8.5和32.5 eV的离子-电子动能关联图使我们能够识别和选择主要的解离光电离过程。本文报道了在hχ(θ=20 eV时H2直接光电离成H2+(2Σg+)离子基态以及在hν=2 8.5和32.5 eV时将H2(q1 1Πu+(1))和H2(q2 1Σu(1))双激发态自电离成H2+(2Σg+)和H2+(2νu+)连续态的分子骨架光电子角分布.结果表明，在Q1(1σu+(1))态自电离到H2+(1sΣg)离子态时，pσu分波和在Q2(1πu(1))态自电离到H2+(2pΠu)连续体中的dσg分波中占主导地位。当电离发生在较大的核间距时，观察到分子骨架的正反向电子发射各向异性。
Dissociative photoionization of H2 induced by VUV linearly polarized synchrotron radiation P has been studied using the (VH+,Ve,P) vector correlation method. The ion–electron kinetic energy correlation diagrams obtained for the three photon excitation energies hν = 20, 28.5 and 32.5 eV enable us to identify and select the dominant dissociative photoionization processes. The Iχ(θe,ϕe) molecular frame photoelectron angular distributions for any orientation χ of the molecular axis with respect to the polarization are reported for direct photoionization of H2 into the H2+(2Σg+) ionic ground state at hν = 20 eV and for the dominant DPI processes involving autoionization of the H2(Q1 1Σu+(1)) and H2(Q2 1Πu(1)) doubly excited states into the H2+(2Σg+) and H2+(2Σu+) continua at hν = 28.5 and 32.5 eV. They show the dominant excitation of a p σu partial wave in autoionization of the Q1(1Σu+(1)) state into the H2+(1s σg) ionic state and that of a d πg partial wave in autoionization of the Q2(1Πu(1)) state into the H2+(2p σu) continuum. A molecular frame forward–backward electron emission anisotropy is observed when ionization takes place at large internuclear distance.