2017 Fiscal Year Final Research Report
Rapid increase events of cosmic-rays in the past three thousand years and there effects on the earth
| Project/Area Number |
26287042
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Partial Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Nagoya University |
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Principal Investigator |
Masuda Kimiaki 名古屋大学, 宇宙地球環境研究所, 准教授 (40173744)
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| Research Collaborator |
MIYAKE Fusa
ITOW Yoshitaka
SAKO Takashi
MATSUMI Yutaka
NAKAYAMA Tomoki
SUZUKI Asami
TAKEUCHI Yuya
MORI Chihiro
KOJIMA Yasusuke
ADACHI Takumi
FUJIMORI Ryuji
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| Project Period (FY) |
2014-04-01 – 2018-03-31
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| Keywords | 宇宙線 / 宇宙高エネルギー現象 / 放射性炭素 / エアロゾル / 雲凝縮核生成 / 太陽活動 |
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| Outline of Final Research Achievements |
Galactic cosmic rays come to the earth under the solar effect and produce 14C nuclei in the atmosphere, being archived in tree rings. Measurement of past 14C content with 1-2 year resolution tells us a detailed history of cosmic ray intensity. Here we obtained characteristics of the sun during AD500-1350. Also we surveyed cosmic ray intensity in a part of past 7000 years and found a rapid increase, being considered to be due to abnormal solar activities.
We confirmed by accelerator experiments using heavy-ions that ion-induced cloud condensation nuclei can be produced from ionization by cosmic-ray particles in atmosphere. Produced ion density and size distributions of produced aerosol particles were measured and no clear change in characteristics of particle production was observed for kind of heavy ion.
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| Free Research Field |
宇宙線物理学
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