| Project/Area Number |
09650233
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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 |
Thermal engineering
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| Research Institution | Shizuoka University |
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Principal Investigator |
ARAKI Nobuyuki Shizuoka University, Faculty of Engineering, Professor, 工学部, 教授 (90005314)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIYAMA Yu Hamamatsu Photonics K.K. Central Research Laboratory, Manager, 中央研究所, 室長
TANG Dawei Shizuoka University, Graduate School for Electronic Science, Research Associate, 大学院・電子科学研究科, 助手 (40262795)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Heat conduction / Non-Fourier Characteristics / Thermal relaxation time / High-speed heating by laser / High-speed temperature response / Thin films / 非フーリエ問題 / 高速温度応答 |
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| Research Abstract |
The purpose of this work is to observe the non-Fourier behaviors in thin films under short laser-pulse heating and to estimate the relaxation times and thermal diffusivities of the materials by measuring high-speed temperature responses at the surface.
In the first stage, the effects of the heating-speed of the laser, the response-speed of the measuring system, and the absorptive coating layer on the observation of temperature responses and the measurement of thermal diffusivities are investigated. In the experimental system, the heating laser is YAG with pulse-width of 16 ns, the measuring system includes : an MCT sensor with time constant of 0.9μs, amplifier of 0.64 μs (gain of 2000), filter of 0.115 μs. The thermal diffusivities of SUS304 films with thickness from 8 to 90 μm are measured. The results for those with thickness thinner than 10 μm show smaller values than the reference data. By introducing a model of m-th order delay in measuring system, the measuring results can be revised to be the same as the reference data. For the effect of the absorptive coating layer, the temperature responses for various kinds of coating materials with different surface structures are compared each other. Some ways to decrease this effect are suggested. In this stage some theoretical preparation for the observation of non-Fourier behaviors have been made.
For the experimental observations of the non-Fourier behaviors, however, because the MCT sensor is too slow, the thermoreflectance technique is employed for measuring the high-speed temperature responses. From the theoretical analysis, the relaxation time will become much bigger in low temperature than that in room temperature. A cryogenic system with optical windows is installed to provide an environment temperature of experiment down to 5.6 K. Until this report was written, the final aim is not reached yet. The results obtained now have the approval of our colleagues in the world.
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