| Project/Area Number |
18540498
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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 |
Plasma science
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| Research Institution | Japan Aerospace Exploration Agency |
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Principal Investigator |
ADACHI Satoshi Japan Aerospace Exploration Agency, Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Associate professor (80358746)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAYANAGI Masahiro Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 宇宙科学研究本部, Senior Researcher (00392811)
MATSUMOTO Satoshi Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 宇宙科学研究本部, Senior Researcher (90360718)
YODA Shin-ichi Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 宇宙科学研究本部, Professor (00344276)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,980,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥480,000)
Fiscal Year 2007: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Complex Plasmas / Plasma Parameter Measurement / Pair Distribution Function / Mean Inter-particle Distance / Self-organization Mechanisms / Coulomb crystal |
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| Research Abstract |
The objective of this research is to investigate the self-organization of the Coulomb crystal in complex plasmas, which will be caused by the attractive and repulsive forces. In order to accomplish this objective, dependencies of the inter-parbcle distance on various conditions are experimentally investigated in 2006. Through the research in 2006, a new hypothesis that the inter-particle distance is determined by the balance between the Coulomb repulsive force and the pushing force from the plasma pressure, which is similar to the attractive force, is obtained. In order to confirm this hypothesis, particles with different diameters are used in 2007. In both cases of monodisperse particles with 1 micrometer and 5 micrometers in diameter, the Coulomb crystals are successfully obtained without any artificial particle-confinement mechanisms. In order to investigate the self-organization mechanisms of the Coulomb crystal, the images of the crystals are obtained first under various gas pressure and rf power conditions. Then, the coordinates of the particles are obtained from the images. By using the coordinates, the pair distribution function are obtained. In addition, the coordination number of the crystal is also obtained from the pair distribution function. From the latter information, the structure can be discussed. From the former information, the inter-particle distance is obtained. The dependencies of the inter-particle distance on the ratio of the square of the surface charge of the particte to length are obtained. In the 1 micrometer case, it was found that the inter-particle distance is proportional to that ratio in 2006. This is the reason why the previous hypothesis is proposed. In 2007, the same dependencies in the case of 5 micrometers are obtained. It is found that this dependency supports the hypothesis. The hypothesis being similar to this one has never been proposed.
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