| Project/Area Number |
05650027
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
表面界面物性
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| Research Institution | Yokohama National University |
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Principal Investigator |
TANAKA Masatoshi Yokohama National University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (90130400)
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| Co-Investigator(Kenkyū-buntansha) |
USAMI Seiji Yokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (40017877)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Laser Desorption / Time-Resolved Luminescence Measurements / Dynamic Processes / Laser Ablation |
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| Research Abstract |
The spatial distribution of desorbed species to pulsed Nd : YAG laser-irradiation and its temporal evolution have been investigated with time-resolved luminescence measurement system. The measurements included three configurations ; spectrum-time, space-time, and monochromatic space-time measurements. The last one has been develped in this study. Following results have been obtained.
1. The plumes which are produced by IR laser (lambda=1064nm, 100J/cm^2) above graphite targets in the air and He gas have three components ; plasma, shock wave driven by the plasma and carbon radicals. The mechanisms for the generation of these components have been clarified.
2. The plumes which are produced by UV laser (lambda=266nm, 5J/cm^2) above Si (lll) surfaces and sintered NiO pellets in high vacuum are separated into three components ; electrons, ions and neutral atoms whose velocities are 10^6,10^5 and 10^4m/s, respectively. Ions move much faster than neutral atoms because of acceleration by electrons which escaped from the plasma. Polar angle-dependence of the velocity of neutral atoms has been obtained.
3. Species desorbed from Si (lll) surfaces under the irradiation of UV laser of below threshold fluence (lJ/cm^2) were detected as a group moving slowly (10^3m/s) with wide velocity distribution.
Above results show that the measurement system developed in this study provides us with useful information about dynamical processes of species ejected by laser desorption. Specifically, high sensitivity of this system is verified by the fact that the species which are not observable have been detected. However, detection of adsorbed species, which is the ultimate goal of this study, has not yet accomplished.
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