Rosen S, Derkatch A, Semaniak J, Neau A, al-Khalili A, Vikor L, Thomas R, Danared H, Larsson M
Department of Physics, Stockholm University, Sweden.
Faraday Discuss. 2000(115):295-302; discussion 303-30. doi: 10.1039/a909314a.
Dissociative recombination of vibrationally relaxed H2O+ ions with electrons has been studied in the heavy-ion storage ring CRYRING. Absolute cross-sections have been measured for collision energies between 0 eV and 30 eV. The energy dependence of the cross-section below 0.1 eV is found to be much steeper than the E-1 behaviour associated with the dominance of the direct recombination mechanism. Resonant structures found at 4 eV and 11 eV have been attributed to the electron capture to Rydberg states converging to electronically excited ionic states. Complete branching fractions for all dissociation channels have been measured at a collision energy of 0 eV. The dissociation process is dominated by three-body H + H + O breakup that occurs with a branching ratio of 0.71.
在重离子储存环CRYRING中研究了振动弛豫的H2O+离子与电子的离解复合。测量了0 eV至30 eV碰撞能量下的绝对截面。发现低于0.1 eV时截面的能量依赖性比与直接复合机制占主导相关的E-1行为陡峭得多。在4 eV和11 eV处发现的共振结构归因于电子俘获到收敛于电子激发离子态的里德堡态。在0 eV的碰撞能量下测量了所有离解通道的完整分支比。离解过程主要由三体H + H + O分解主导，其分支比为0.71。
