@article{oai:nagoya.repo.nii.ac.jp:00011861, author = {北澤, 恭平 and Kitazawa, Kyohei and 永冶, 健太朗 and Nagaya, Kentaro and 増田, 公明 and Masuda, Kimiaki and 中村, 俊夫 and Nakamura, Toshio and 宮原, ひろ子 and Miyahara, Hiroko and 村木, 綏 and Muraki, Yasushi}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {The sunspot number, which is a typical index of solar activity, shows a clear 11-year periodicity called the Schwabe cycle. However, in the period around 1645 to 1715 AD the sunspots were almost absent on the solar surface. This is considered to be due to extraordinary weakening of solar activity and this period is called the Maunder minimum. We cannot know from the sunspot record if the Schwabe cycle continued or not in the Maunder minimum. Also we cannot know the periodicity of solar activity without sunspot observation as in pre-telescope era. So we use carbon 14, which is one of cosmogenic nuclides as an indirect index of solar activity with inverse correlation, in order to study 11-year periodicity during grand solar minima like the Maunder minimum. Stuiver classified grand solar minima into two types by duration of minima. The Maunder-type minima have a duration of 〜80yr whereas the Spoerer-type minima last 〜120yr. We previously measured carbon 14 content in Japanese tree for the Maunder minimum (the Maunder type), the Spoerer minimum (the Spoerer type) and the 4^