1987 Fiscal Year Final Research Report Summary
Polarization Plasma Spectroscopy Excitation Anisotropy by Optical, Electron Collision and Atomic Collision Excitation
| Project/Area Number |
61460229
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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 |
プラズマ理工学
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| Research Institution | Kyoto University |
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Principal Investigator |
FUJIMOT Takashi Faculty of Engineering, Kyoto University, Associate Professor, 工学部, 助教授 (90026203)
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| Co-Investigator(Kenkyū-buntansha) |
OKASAKA Rei Faculty of Engineering, Kyoto University, Assistant, 工学部, 助手 (10026065)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Plasma Spectroscopy / Photo-excitation / Collisional-excitation / Relaxation of anisotropy / シュタルク拡がり |
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| Research Abstract |
Anisotropic excitation, optical or collisional, creates alignment in the excited-state atoms or ions, and these group of atoms or ions emits radiation that has a spatially anisotropic intensity distribution and is polarized. The objective of the present research was to investigate the general characteristics of the alignment produced by an optical excitation or by ion-atom collisions and to inviestigate the alignment relaxation, or disalignment, due to various collision processes, especially electron collisions.
The basic formalism describing the optical excitation of atoms had already been developed by us. In the present study we have applied this formalism so as to develop a new method of determinations of atomic transition probabilities and lifetimes. Validity of our method has been demonstrated. As a basis for the following experiment we studied spectroscopically a pulsed helium discharge plasma. The existence of the ionizing phase plasma and the recombining phase one was demonstrated by the measurement of the population density distribution of the excited atoms, and the predicition by one of us was confiremed. By using the afterglow plasma the laser-induced-fluorescence-spectrosocpy(LIFS) was applied to neon excited atoms in the helium-neon mixture afterglow plasma, where the excitation was made with linearly polarized light. By observing the temporal developments of polarized components of the emission radiation disalignment of the excited atoms due to electron collision was observed. The magnitude of the rate coefficient was found to be close to that for Stark broadening of the transition lines from this state.
In helium-ion helium-atom collisions polarization of emission radiation was measured as a function of impact energy. The observed complicated behavior is qualitiatively interpreted by the two level model wite inclusion of the locking radius.
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