Exploration of Beryllium Calcination Condition for the High-Resolution 10Be Analysis of Cosmic Ray Events
Kayo Kanzawa1, Fusa Miyake1, Kazuho Horiuchi2, Ryuji Fujimori1, Takeyasu Yamagata3, Hiroyuki Matsuzaki3
1Nagoya University, Nagoya, Japan, 2Hirosaki University, Hirosaki, Japan, 3University of Tokyo, Tokyo, Japan
High-resolution analyses of cosmogenic 10Be in polar ice cores have been performed to investigate the past cosmic ray events. For such high-resolution 10Be analyses in ice core sample, we introduced a new beryllium calcination system to convert Be(OH)2 to BeO at the Institute for Space-Earth Environmental Research (ISEE), Nagoya University. We explored the several conditions to prepare BeO samples with low 10B background, i.e., a calcination in the air, vacuum, and oxygen conditions. We also tested the calcination temperature from 240℃ to 730℃, and we confirmed sufficient BeO− beam current was obtained from these samples. Although it has been expected that Be(OH)2 is not completely converted to BeO at lower temperature less than 400℃, the results suggest that the BeO samples for the AMS measurement can be obtained at such a lower temperature.
Some of the authors study past solar energetic particle events by analyzing cosmogenic nuclides (10Be in ice cores and 14C in tree rings).