| Project/Area Number |
11640397
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物理学一般
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| Research Institution | Yamaguchi University |
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Principal Investigator |
KIMURA Mineo Yamaguchi University, Faculty of Engineering, Professor, 工学部, 教授 (00281733)
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| Co-Investigator(Kenkyū-buntansha) |
SUEOKA Osamu Yamaguchi University, Faculty of Engineering, Professor, 工学部, 教授 (00012378)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Electron and positron impacts / Vibrational excitation / Resonance / Scattering dynamics / Quadrupole interaction / Dipole moment / 共鳴 / 散乱断面積 / C_6H_6分子 / C_6F_6分子 / 電子散乱 / 陽電子散乱 / CF_3I分子 / CH_3I分子 / 全散乱断面積 / CO_2分子 / OCS分子 |
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| Research Abstract |
Due to the difference in charge, electrons (e^-) and positrons (e^+) are expected to provide quite different interaction scheme and dynamical mechanisms upon collisions with atoms and molecules. We have investigated vibrational excitation in CO_2 and OCS molecules by (e^-) and e^+ impacts, because both molecules are linear molecules, but OCS molecule has a weak dipole moment while CO_2 has no dipole. We have observed a strong vibrational mode-dependence for vibrational excitation in e^+ and e^- scattering from CO_2 for the first time ; for the symmetric stretching (100) mode, vibrational excitation cross section by e^- scattering is larger by two-three orders of magnitude than that by e^+ scattering, while the cross sections for asymmetric stretching (001) and bending (010) modes are rather similar. Our experimental results are qualitatively consistent to theoretical findings. The weak quadrupole interaction and long-range strong dipole interaction in a combination with the coupling matrix element are responsible to the cause. In addition, the presence of the resonance-like structures was abundantly observed.
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