1997 Fiscal Year Final Research Report Summary
Development of a cryogenic air sampling system for unmanned aircraft observation.
| Project/Area Number |
07558076
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 |
WADA Makoto National Institute of Polar Research, Division of Research, Associate Professor, 研究系, 助教授 (40132716)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIKAWA Kozue Nissan Syoji Co.Ltd., Manager of Research Division, 企画部ATプロジェクト研究担当, 部長
YAJIMA Nobuyuki Institute of Space and Astronautical Science, Research Division, Professor, システム研究系, 教授 (30200489)
MORIMOTO Shinji National Institute of Polar Research, Arctic Environment Research Center, Resear, 北極圏環境研究センター, 助手 (30270424)
SHIOBARA Masataka National Institute of Polar Research, Center for Antarctic Environment Monitorin, 南極圏環境モニタリング研究センター, 助教授 (60291887)
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| Project Period (FY) |
1995 – 1997
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| Keywords | cryo pump / adiabatic expansion / greenhouse gas |
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| Research Abstract |
In order to clarify distributions and variations of atmospheric trace gases in the stratosphere using an unmanned aircraft, it is necessary to develop a small and light weight air sampling system. For this purpose, we developed and tested a new cryogenic air sampler using neon Joule-Thomson (JT) cooler. The results are summarized as follows :
1. An refrigeration capacity of neon JT cooler was experimentally determined. The results showed that the neon JT cooler produced refrigeration of about 23 Joule/second at neon gas pressure of 130 kgf/cm^2 and of nearly zero at 50 kgf/cm^2. It was also confirmed that the neon gas was liquefied after 50 to 150 seconds of the neon gas introduction.
2. Low pressure nitrogen was introduced into a new cryogenic air sampling system in which the JT cooler was equipped, and sampling rate of nitrogen were measured. the sampling rate was between 0.7 and 1.0 normal litter/minutes at nitrogen pressure of 100 hPa and between 0.3 and 0.7 normal litter/minutes at 5 hPa. these results indicate that it is necessary to increase the sampling rate to realize a practical sampling system.
3. To examine the composition of air after sampled by the cryogenic sampling system, an air-base standard gas, of which methan concentration was already determined, were introduced into the sampling system and sampled cryogenically. As a result, the methan concentration of the sample was confirmed to be identical to that of the standard gas within the measurement precision.
4. A high conductance valve system was successfully developed using a pipe breaking cutter, cold weld and N-S joint techniques. Because the valve system was composed only by straight tubes, high conductance was easily attained even if relatively thin tube was used.
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