| Budget Amount *help |
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Research Abstract |
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.
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