1992 Fiscal Year Final Research Report Summary
Study on Fundamental Processes and their Control of Condensation and Evaporation by Laser Excitation
| Project/Area Number |
02402027
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KOTAKE Susumu Tokyo Univ.,Faculty of Engng.,Professor, 工学部, 教授 (30013642)
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| Co-Investigator(Kenkyū-buntansha) |
MARUYAMA Shigeo Tokyo Univ.,Faculty of Engng.,Lecturer, 工学部, 講師 (90209700)
SYOJI Masahiro Tokyo Univ.,Faculty of Engng.,Professor, 工学部, 教授 (00011130)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Control of Condensation and Vaporization / Molecular Cluster / Laser Thermal Excitation |
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| Research Abstract |
The aim of the present study is to understand the fundamental process of condensation and evaporation from the standpoint of molecular clustering and the possibility of controlling the process with the thermal excitation method by using lasers. For the purpose, atomic/molecular beams of metal and nonmetal vapors were produced by the laser and electron-beam heating method. Clusters formed in the condensation process of these beams were irradiated by a laser beam to be excited on thermal level before striking a film condensate of which thickness were measured by a film thickness meter. The effects of the laser intensity and irradiation conditions on the features of film condensation also were investigated with a quadruple mass spectrometer and FTIR analyzer. It is found that the condensation rate can be changed by the laser irradiation. These effects of laser irradiation depend on the clustering process; the more clusterized the vapor atoms are, the more remarkable affect would be observed and the finer structure of the condensate could be obtained. The irradiation has little effect for vapors which are hardly clusterized. The laser of smaller wave lengths or higher energies has more intense effect on the condensation process. This can be attributed to the change in the intermolecular potential between molecules or atoms of clusters by laser irradiation rather than the change in their thermal energy. From these result, the possibility to control the fundamental process of condensation by laser irradiation has been evidenced.
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