Study of highly excited states of molecules by an ion-energy-loss spectroscopy

通过离子能量损失光谱研究分子的高激发态

• 批准号: 04640389
• 负责人: KOBAYASHI Nobuo
• 金额: $ 1.34万
• 依托单位: Tokyo Metropolitan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640389/
• 关键词: High resolution ion energy-loss spectroscopy; Highly excited states; Simultaneous transitions in projectiles and targets; 衝突・標的同時遷移; イオン-分子衝突; 分子の振動励起

The purpose of this study is as follows. (1) Improvement of the resolution and the brightness of an ion energy-loss spectrometer. (2) Survey of highly excited states of molecules. By modifying the ion extraction electrode of the electron impact type ion source and focussing lens system, the intensity of the ion beam was improved enough to measure energy loss spectra up to about 16eV in collisions of 2.5 keV He^+ with n_2 and CO molecules. Some unidentified peaks were found above 12 eV in N_2 molecule with the energy resolution of 60 meV.Energy spectra of H_3^+ ions in collisions with rare gases (He, Ne, Ar, Kr and Xe) were measured. In the energy range of 0-1 eV of energy loss and gain sides, broad peaks were observed. These peaks may be due to the excitation and de-excitation among ro-vibronic states of H_3^+. This fact suggests that about half of H_3^+ ions formed in the ion source are excited states. In addition to these peaks, broad energy loss peaks located at around 10 eV were observed for Ar, Kr and Xe targets. These peaks are attributed to simultaneous transitions of the excitation in the targets and the excitation or de-excitation in the projectile H_3^+ ions.

本研究的目的如下。(1)提高离子能量损失光谱仪的分辨率和亮度。(2)分子高激发态综述。通过改进电子撞击型离子源的离子引出电极和聚焦透镜系统，使离子束的强度提高到足以测量2.5keV He~(2+)与N_2和CO分子碰撞的能量损失谱，最高可达16 eV。在能量分辨率为60 meV的N_2分子中发现了一些在12 eV以上的未知峰。测量了H_3~+离子与稀有气体(He、Ne、Ar、Kr和Xe)碰撞的能谱。在能量损失端和增益端的0-1 eV能量范围内，观察到了宽峰。这些峰可能是由于H_3~+的非振动态之间的激发和失激所致。这一事实表明，在离子源中形成的H_3~+离子中约有一半是激发态。除了这些峰外，对于Ar、Kr和Xe靶，还观察到了位于10 eV左右的宽能量损失峰。这些峰值归因于靶中激发和入射H_3~+离子激发或去激发的同时跃迁。