Development of Time and Space Resolved 2-Dimensional Penning Ionization Electron Spectroscopy

在本研究项目中，我们开发了一种利用时间分辨成像技术研究光-潘宁电离光谱的新装置。随着新实验系统的建立，我们还将碰撞能分辨彭宁电离光谱应用于有机分子、过渡金属-分子配合物和非挥发性分子等多种分子。在新型实验装置的研制方面，我们建立了各种团簇及其离子的光-潘宁电离光谱装置。该装置由五个差分真空室组成：(1)激光汽化簇离子源，(2)簇离子质量分离的飞行时间质谱仪，(3)磁瓶式电子能量分析仪，(4)产生稀有气体亚稳原子束的喷嘴放电源，(5)产生纯和脉冲亚稳原子束的部分。我们开始了大小选择簇负离子的激光光电子能谱实验。首先对飞行时间质谱仪和磁瓶光电子能量分析仪对硅簇负离子Si_n的性能进行了测试。其次，利用该技术研究了铜簇与NO分子的反应体系。特别是，我们发现Cu_2N^-离子至少有两种不同的异构体：一种是Cu_2^-的结构，与N原子弱结合，另一种是紧密结合的结构。在磁瓶电子能谱仪上也进行了成像检测。发现光电子图像是原始图像的近7倍，结果几乎与预测一致。最后，我们正在优化新型亚稳原子束的性能。经过优化后，我们可以开始进行簇的Penning电离光电子能谱实验。

In this research project, we have developed a new apparatus for the study of photo-and Penning ionization spectroscopy by utilizing time-resolved imaging technique. Along with the development of a new experimental system, we also applied collision-energy-resolved Penning ionization spectroscopy to various molecules including organic molecules, transition metal-molecule complexes, and nonvolatile molecules.As for the development of a new experimental apparatus, we construced an apparatus for the photo-and Penning ionization spectroscopy of various clusters and their ions. The apparatus consists of five-differentially evacuated chambers : (1) laser vaporization cluster ion source, (2) time-of-flight mass spectrometer for the mass-separation of the cluster ions, (3) magnetic-bottle-type electron energy analyzer, (4) nozzle discharge source for the production of rare-gas metastable atom beam, and (5) part for the production of pure and pulsed metastable beam. We have started experiment of the laser photoelectron spectroscopy of size-selected cluster negative ions. First we the checked performance of the time-of-flight mass spectrometer and the magnetic-bottle photoelectron energy analyzer for the silicon cluster negative ions, Si_n. Next the system of copper clusters reacted with NO molecules are investigated by this technique. Especially, the Cu_2N^- ions are found to have at least two different isomers : one has a structure of Cu_2^- with which an N atom is weakly bound, and another has a tightly bound structure. The imaging detection was also carried out in the magnetic-bottle electron spectrometer. The photoelectron image are found to be the one magnified almost 7 times from the original, which was a result almost as predicted. Finally, we are now optimizing the performance of the new metastable atomic beam. After this optimization, we can start the experiment of Penning ionization photoelectron spectroscopy of clusters.