A Study of the Chemical Evolution by the Molecular-beam Epitaxy Method

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We constructed the following apparatus in order to simulate the chemical evolution of organic molecules in space and to study the catalytic effect of the surface of minerals.1. A glass-made molecular beam apparatus. The plasmic gas mixture produced by high-frequency discharge was injected on a mineral substrate under high vacuum. Montmorillonite was found to absorb the resulting molecules which yielded amino-acids by hydrolyzation.2. A molecular-beam epitaxy apparatus. The experimental condition can be monitored by a mass-spectrometer. The substrate temperature can be controled between the liquid-nitrogen temperature and 150 C. Various kinds of techniques to activate the gas mixture were used, such as the high-frequency discharge, thermal ionization, catalytic reaction at a high temperature, among which the last one by the use of magnetite was found to be the most effective. The microwave discharge technique is now planned.3. A microwave chemical vapor deposition apparatus. Amino-acid formation in the Titan atmosphere was simulated. When magnetite was placed, the formation of amino acids seemed to occur both by the radical reaction by the discharge and by the catalytic reactin of the Fischer-Tropsch type.The thin films on the mineral surface produced by the above-mentioned experiments were analyzed partly by the liquid chromatography after hydrolyzation, partly by the electron diffraction analysis which was unsuccessful, and partly by the infra-red reflection spectroscopy. The simulation of organic,cosmic dust formation is now planned.