| Project/Area Number |
10640410
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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 |
固体地球物理学
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| Research Institution | Kochi University |
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Principal Investigator |
SASAKI Hiroshi Kochi University, Department of Physics, Professor, 理学部, 教授 (80036566)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Tohru Kochi University, Department of Physics, Assistant, 理学部, 助手 (90243815)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Plate Antenna / EM Wave in the Sea / ボールアンテナ |
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| Research Abstract |
We succeeded to develop the plate antenna for the deep sea bed and obtained information on the electrical environment at the sea bed. The plate antenna system consist of two stainless steal plates of 20cm X 20cm X 1mm and the amplifier circuit with a gain of 2X10^4 in amplitude and the DAT for the data recording housed in a glass sphere. The performed minimum detectable amplitude of the system is 0.1 micro-Volts in the sea when we utilize the FWT (First Wavelet Transfer) method. So if we use the plate antenna with lOOm span, the minimum detectable voltage will be 10 nV.
Due to the trouble of the floating device (Model TR6000, Benthos Inc), observation performed at the shallow sea bed instead of the deep sea bottom, more than lOOOm in depth. The observed electric field at depth 50m, near Usa bay is less than +- 10.5 micro volts which is governed by circuit noises.
Comparison with the data of the EM pulses on land measured by the ball antenna and in the sea at depth 20m, we showed that the pulses under the segment layer of a thickness of 20m equivalent of sea water, can be detected with the present system in the case of their amplitude more than 100 mV.
Moreover, we estimated the amplitude of the commercial AC signals at the 50m depth, at 5.47 km away from the Usa sea shore, as +-63 nV/m.
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