权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Laser Photodetachment Photoelectron Spectroscopy of Negative Ton Metal Clasters

负吨金属碎屑的激光光分离光电子能谱

基本信息

批准号：
62470016
负责人：
ACHIBA Yohji
金额：
$ 3.84万
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 (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

In the course of this project, first, we tested a machine which has newly been construdted for accomplishment of the proposed photodetachment photolelctron spectroscopic studies of metal clusters. The experimental set-up developed for this purpose consists of mainly three parts, i.e., a cluster beam source, a time of flight mass spectrometer, and a photodetachment photoelectron spectrometer. The negative ion metal clusters to be examined were produced by a laser vaporization method combined with a supersonic beam technique. Both of fundamental and second harmonics of a Nd-YAG pulsed laser coupled with a synchronized pulsed nozzle were used for production of internally cold metal ion clusters. Using this machine, we found that the cluster size distributions , for example, in the case of carbon negative ion clusters, extend up to n = 50. Second, we tried to perform mass selection experiments by a time of flight mass spectromener. The time of flight spectrometer used here consists of a pulsed acceleration field and a 1 m field-free flight tube. Using the most suitable experimentally determined parameters, we were able to find the mass resolution up to 100. This was found to be enough to perform the following photodetachmant experiments. Finally, we carried out photodetachment experiments of negative ion clusters which were prior mass selected. A NdYAG pulsed laser (second and third harmonics) was used for this purpose, where the laser firing time against the acceleration pulse was chosen so that only a certain mass number of the clusters was selectively excited. As a conclusion, we were satisfactorily able to detect photodetechment spectra of mass selected negative ion clusters of carbon, Al, Fe and Cu. We are now still trying to accomplish the present methodology as well as to carry out the experiments for understanding the nature of metal clusters.

在这个项目的过程中，首先，我们测试了一台机器，这是最近被任命为完成所提出的金属团簇的光剥离光电子光谱研究。为此目的开发的实验装置主要由三部分组成，即，团束源、飞行时间质谱仪和光剥离光电子光谱仪。负离子金属团簇是用激光蒸发法结合超声束技术制备的。利用Nd YAG脉冲激光器的基波和二次谐波与同步脉冲喷嘴耦合产生内冷金属离子团簇。使用这台机器，我们发现团簇的大小分布，例如，在碳负离子团簇的情况下，扩展到n = 50。第二，我们尝试通过飞行时间质谱仪进行质量选择实验。这里使用的飞行时间谱仪由脉冲加速场和1米无场飞行管组成。使用最合适的实验确定的参数，我们能够找到的质量分辨率高达100。发现这足以进行以下光致发光实验。最后，我们对预先选定质量的负离子团簇进行了光剥离实验。一个NdYAG脉冲激光器（第二和第三谐波）用于此目的，其中对加速脉冲的激光发射时间进行选择，使只有一定质量数的集群被选择性地激发。结果表明，我们能满意地探测到碳、铝、铁和铜等负离子团簇的质量选择性光探测光谱。我们现在仍在努力完成现有的方法学，以及进行实验，以了解金属团簇的性质。