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

在本研究项目中，我们利用时间分辨成像技术研制了一种研究光致电离和潘宁电离光谱的新装置。在开发新的实验系统的同时，我们还将碰撞能量分辨Penning电离光谱应用于各种分子，包括有机分子、过渡金属-分子络合物和非挥发性分子。该装置由五个真空腔组成：(1)激光蒸发团簇离子源，(2)飞行时间质谱仪，(3)磁瓶式电子能量分析器，(4)用于产生稀有气体亚稳原子束的喷嘴放电源，(5)用于产生纯和脉冲亚稳原子束的部分。我们已经开始了尺寸选择的团簇负离子的激光光电子能谱实验。首先，我们考察了飞行时间质谱仪和磁瓶光电子能量分析仪对硅团簇负离子Sin的测量性能，然后用该技术研究了铜团簇与NO分子的反应体系。特别是Cu2N^-离子至少有两种不同的异构体：一种是与N原子弱结合的Cu2^结构，另一种是紧密结合结构。在磁瓶电子能谱仪上也进行了成像检测。光电子图像被发现比原始图像放大了近7倍，这一结果几乎与预测的结果一致。最后，我们现在正在优化新亚稳原子束的性能。优化后，我们可以开始团簇的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.