Measurement of cosmogenic nuclides in meteorites by well-type Ge detector in Ogoya Underground Laboratory. Correction of coincidence sum effect for Al-26, Co-56, Na-22, and Co-60

Two carbonaceous chondrite samples of about 3 ∼ 5g, which have fallen in California on April 22, 2012, were measured by well-type Ge detector in Ogoya Underground Laboratory from May 21, 2012 for 30 days. Cosmogenic Co57, Cr51, Be7, Co58, Mn54, Co56, Co60, Na22, and Al26 were detected within the error of 20% or less, (That of Al26 is about 33%). The correction of coincidence sum effect would require for Al26, Co56, Na22 and Co60. The correction factors of these nuclides have been estimated from total efficiency as a function of gamma-ray energy. (author)