Two-dimensional Penning Ionization Electron Spectroscopy of CH_3I and CH_2I_2 by He*(2^3S) Metastable Atoms
Two-dimensional Penning Ionization Electron Spectroscopy of CH_3I and CH_2I_2 by He*(2^3S) Metastable Atoms
复制标题
He*(2^3S)亚稳态原子CH_3I和CH_2I_2的二维潘宁电离电子能谱
DOI：
10.1088/1742-6596/235/1/012014
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
and Koichi Ohno
中科院分区：
文献类型：
--
作者：
Naoki Kishimoto;Andriy Borodin;Takuya Horio;Masakazu Yamazaki;and Koichi Ohno
用碰撞能/电子能分辨二维潘宁电离电子能谱(2D-PIES)研究了碘甲烷(CH3 I)和二碘甲烷(CH2 I2)与亚稳态He(2 3 S)原子碰撞时的潘宁电离.部分电离截面的碰撞能量依赖关系表明，在低碰撞能下，与价分子轨道周围的He*(2 3 S)原子的相互作用是吸引的，唯一的碘甲烷σCH分子轨道区域在正常碰撞能范围内(70-35 0 meV)具有排斥性.在pies谱中，较低电子能量(3.7-5.5 eV)的大带被归因于瞬时离子对的自电离。相关的入射电离通道具有吸引人的特性。激发转移是导致I**自电离的主要原因，它发生在接近碳原子的区域，在正常碰撞能量范围内对He*(23 S)是排斥的。(He-CH2I2)**的超激发络合物通过发生在靶的σCI区附近的激发转移而自电离。
Penning ionization of iodomethane (CH 3 I) and diiodomethane (CH 2 I 2) upon collision with metastable He*(2 3 S) atoms was studied by collision-energy/electron-energy resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES) over a wide range of collision energies (20–350 meV). Collision energy dependence of partial ionization cross sections (CEDPICS) indicates that the interaction with He*(2 3 S) atoms around the valence molecular orbitals is attractive at low collision energies except for the only σ CH molecular orbital region of iodomethane which has a repulsive character in the normal collision energy range (70–350 meV). Large bands at lower electron energies (3.7–5.5 eV) in PIES spectra were ascribed to autoionization from a transient ion-pair. The related entrance ionization channel has an attractive character. The excitation transfer, which is responsible for the I** autoionization, takes place in regions close to carbon atoms and is repulsive towards He*(2 3 S) in the normal collision energy range. The superexcited complex of (He-CH 2 I 2)** autoionizes via the excitation transfer occurring close to the σ CI regions of the targets.