Measurements of reaction dynamics of excited metastable atoms with molecules by using pseudorandom discharge

利用伪随机放电测量激发亚稳态原子与分子的反应动力学

• 批准号: 11640499
• 负责人: TOKUE Ikuo
• 金额: $ 2.3万
• 依托单位: NIIGATA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640499/
• 关键词: Metastable Helium Atom; Reaction Dynamics; Emission Spectrum; Penning Ionization; Dissociation; Reaction Cross Section; Rovibrational Distribution; 準安定へリウム原子; 反ダイナミックス; 発光スペクトル; 発光断面積; 準安定励起原子

A CCD detector has been introduced to measure emission spectra produced by collisions of excited metastable helium atoms with target molecules. According to this method, the time spent has been remarkably reduced and the observed spectra are free from the drift of the intensity of helium beam. Nevertheless, the time for measurement was limited up to 5 minutes because of shot noises caused by cosmic ray. In order to prepare observed spectrum we have to do the following procedures : (1) elimination shot noises one by one, (2) addition a couple of data files, and (3) correction sensitivity for each pixel. We have developed a new algorithm to eliminate shot noises.In this study, we have measured with high resolution the NH(A-X, c-a) spectra produced from NH_3 target, the HCl^+(A-X) and HBr^+(A-X) spectra from HCl/HBr target, and the SH^+(A-X) spectra from H_2S target, and achieved to determine the rovibrational distributions by improving the accuracy for the synthetic spectrum that compares with the observed spectrum. Accordingly, bimodal distributions of the rotational populations for HCl^+(A, v'=0) and HBr^+(A, v'=0) have been found at first. The rotational excitation observed for HCl^+ (A, v'=0) has been clarified by analyzing the wave packet, which propagates on the incident and exit potential surfaces. The method developed in this study can be applied to ionization and dissociation in general.

采用CCD探测器测量了亚稳态氦原子与靶分子碰撞产生的发射光谱。该方法大大缩短了测量时间，而且测量结果不受氦束强度漂移的影响。然而，由于宇宙射线引起的散粒噪声，测量时间被限制在5分钟以内。为了准备观测光谱，我们必须做以下步骤：（1）逐个消除散粒噪声，（2）添加几个数据文件，（3）校正每个像素的灵敏度。我们提出了一种新的算法来消除散粒噪声。在这项研究中，我们测量了高分辨率的NH NH_3靶产生的（A-X，c-a）谱，HCl/HBr靶产生的HCl^+（A-X）和HBr^+（A-X）谱，H_2S靶产生的SH^+（A-X）谱，并通过提高合成光谱与观测光谱比较的精度来实现对振转分布的确定。据此，首次发现了HCl^+（A，v '= 0）和HBr^+（A，v'= 0）的转动布居的双峰分布。通过分析在入射势面和出射势面上传播的波包，阐明了HCl^+（A，v '= 0）的转动激发。在这项研究中开发的方法可以适用于一般的电离和解离。

项目成果

K. Yamasaki, A. Watanabe, T. Kakuda, and I. Tokue: "Deactivation rate constants of OH(X^2Π_i, v = 1-4) by collisions of NH_3"J. Phys. Chem.. 104/40. 9081-9086 (2000)

K. Yamasaki、A. Watanabe、T. Kakuda 和 I. Tokue：“NH_3 碰撞导致 OH(X^2Π_i, v = 1-4) 的失活速率常数”J. Phys. 104/40。 9081-9086 (2000)

I. Tokue, H. Tanaka, K. Yamasaki, and S. Nanbu: "Formation of HCl^+(A^2Σ^+) and HBr^+(A^2Σ^+) resulting from He(2^3S) Penning ionization of HCl and HBr"J. Phys. Chem.. 106 (in press). (2002)

I. Tokue、H. Tanaka、K. Yamasaki 和 S. Nanb​​u：“由 He(2^3S) Penning 形成 HCl^+(A^2Σ^+) 和 HBr^+(A^2Σ^+) HCl 和 HBr 的电离”J. Phys. Chem.. 106（印刷中）。（2002 年）

I. Tokue, H. Tanaka, and K. Yamasaki: "Photoemission cross sections for fragments and molecular ions produced by collisions of He(2^3S) atoms with SiCL_4 and GeCl_4"Bull. Chem. Soc. Jpn.. 72/9. 2067-2072 (1999)

I. Tokue、H. Tanaka 和 K. Yamasaki：“He(2^3S) 原子与 SiCL_4 和 GeCl_4 碰撞产生的碎片和分子离子的光发射截面”Bull。

Ikuo Tokue: "Photoemission Cross Sections for Fragments and Molecular Ions produced by Collision of He(2^3S) Atoms with SiCl_4 and GeCl_4"Bull. Chem. Soc. Jpn.. 72・9. 2067-2072 (1999)

Ikuo Tokue：“He(2^3S) 原子与 SiCl_4 和 GeCl_4 碰撞产生的碎片和分子离子的光发射截面”Soc.Jpn.72・9。

徳江 郁雄: "Dhotoemission cross sections for fragments and molceular ions produced by collisions of He(2^3s) atoms with SiCl_4 and Gell4"Bull. Chem. Soc. Jpn.. 72. 2067-2072 (1999)

Ikuo Tokue：“He(2^3s) 原子与 SiCl_4 和 Gell4 碰撞产生的碎片和分子离子的 Dhotoemission 截面”Chem. 72. 2067-2072 (1999)