Search for extreme SPE for the past 2500 years using cosmogenic nuclides

2016 Fiscal Year Final Research Report

• Project/Area Number: 26887019
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nagoya University
• Principal Investigator: MIYAKE Fusa 名古屋大学, 高等研究院(宇宙), 特任助教 (90738569)
• Project Period (FY): 2014-08-29 – 2016-03-31
• Keywords: 宇宙線生成核種 / 大規模SPE / 放射性炭素

Outline of Final Research Achievements

It is considered that 14C contents in tree rings and 10Be concentrations in ice cores would record the past incoming cosmic ray intensities. The purposes of this study are to specify the origin of the annual cosmic ray increase event in AD 775, and to search for other cosmic ray events.
We showed that the plausible origin of the 775 event is an extreme SPE (or several SPEs) by measuring 10Be concentrations in the Dome Fuji ice core in the Antarctica. Also we showed an extreme annual event comparable to the 775 event is very rare, and found a different type of cosmic ray increase event by 14C measurements for the BC time period.

Free Research Field

宇宙線生成核種