| Project/Area Number |
10558086
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | National Institute of Polar Research |
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Principal Investigator |
YAMANOUCHI Takashi National Institute of Polar Research, Professor, 南極圏環境モニタリング研究センター, 教授 (00141995)
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| Co-Investigator(Kenkyū-buntansha) |
HIRASAWA Naohiko National Institute of Polar Research Research Associate, 情報科学センター, 助手 (10270422)
MORIMOTO Shinji National Institute of Polar Research Research Associate, 北極圏環境研究センター, 助手 (30270424)
HASHIDA Gen National Institute of Polar Research Research Associate, 南極圏環境モニタリング研究センター, 助手 (00280537)
ISHIKAWA Kozue Nissan Shoji Co.Ltd. Manage of Research Division, 企画部, 技術研究担当部長
AOKI Shuji Tohoku University Associate Professor, 大学院・理学研究科, 助教授 (00183129)
和田 誠 国立極地研究所, 研究系, 助教授 (40132716)
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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 |
¥12,900,000 (Direct Cost: ¥12,900,000)
Fiscal Year 2000: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1998: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | cryo pump / adiabatic expansion / greenhouse gas / stratosphere |
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| Research Abstract |
In order to clarify distributions and variations of greenhouse gases in the stratosphere, it is necessary to develop a small and light weight air sampling system that can be used with a small balloon. For this purpose, we have developed a new cryogenic air sampler using adiabatic expansion of high pressure neon gas. In the present study, we produced prototypes of the sampler and performed air sampling experiments with three kinds of cryo-head. The results obtained are summarized as follows :
It was confirmed that the temperature at the cryo-head decreased down to the liquefied point of neon (27K) after 150 to 240 seconds of neon gas introduction. Air sample, of which pressure was set to be from 25 to 200 hPa, was collected cryogenically by the sampling system at a rate from 0.4 to 1.2 standard litters per minute. Total amount of the collected air sample was about 6.0 and 3.0 standard liters when the sample pressures were 25 and 200 hPa, respectively.
The sampling rate measured by a mass flow meter showed different patterns depending on the sample pressure. When the sample pressure was below 60 hPa, the air sampling continued at least 10 minutes. On the other hand, for the air sample above 120 hPa, the air sampling terminated about 3 minutes after the sampling started. The cause of the difference was seemed to be the fact that the temperature of a part of the cryo-head was above the melting point of oxygen for the air sample above 120 hPa. To obtain more amount of air sample, further modifications should be made for the cryo-head.
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