1995 Fiscal Year Final Research Report Summary
Study of photodesorption dynamics by using pulsive synchrotron radiation
| Project/Area Number |
05452045
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | Okazaki National Institutes |
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Principal Investigator |
KAMADA Masao Okazaki National Institutes, Institute for Molecular Science, Associate Professor, 分子科学研究所, 助教授 (60112538)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Shin-ichiro Okazaki National Institutes, Institute for Molecular Science, Research Associate, 分子科学研究所, 助手 (00227141)
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| Project Period (FY) |
1993 – 1995
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| Keywords | Photodesorption / Time response / Surface Dynamics / Ionic crystal / Alkali atom / Excited state alkali / LIF |
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| Research Abstract |
The purpose of the present project is to investigate photodesorption dynamics on solid state surfaces. The followings are the results of the present projects :
(1) By using synchrotron radiation covering wide energy range and quasi-monochromatic intense undulator radiation, desorption of excited-state alkali atoms were observed in the energy ranges corresponding to the valence and core level excitations. This means that desorption is caused by valence excitation as well as core-level excitation.
(2) Temperature, irradiation dose, and substance dependences of the desorption intensities were very different between excited-state alkali atoms and ground state alkali atoms.
(3) Time response of the excited-state alkali atoms was successfully observed by using pulsive synchrotron radiation. The time response consisted of a nano-second component and a slow component between micro and milli-seconds, indicating two (fast and slow) desorption mechanisms.
(4) Signal of the Laser-Induced-Fluorescence was obtained on ground state potassium atoms from KCl and KBr. By changing the timing between synchrotron radiation and a diode laser, the time response of the ground-state alkali desorption was observed for the first time in the world. Any existing model cannot explain the fast desorption of the ground-state alkali atoms.
(5) Photodesorption experiments were carried out in the same chamber as the photoelectron spectrometer to know the effects of the adsorbates on the solid surfaces.
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