@article{oai:nagoya.repo.nii.ac.jp:00012851,
 author = {窪田, 卓見 and 馬原, 保典 and 太田, 朋子 and 中村, 俊夫 and KUBOTA, Takumi and MAHARA, Yasunori and OHTA, Tomoko and NAKAMURA, Toshio},
 journal = {名古屋大学加速器質量分析計業績報告書},
 month = {Mar},
 note = {Quartz samples, which were collected at up to 70 cm (120 g/㎠) at northern Abukuma region, Japan, natural graphite, and copper oxide were heated up to 1900 ℃. In this heat treatment C-14 was extracted from melt quartz and natural graphite was oxidized with copper oxide to carbon carrier gas. In order to decrease background in our extraction system, natural graphite was used as precursor of carrier gas because natural graphite has low C-14 content and it is unlikely that isotopic exchange occurs with atmospheric carbon during storage. AMS measurement of natural graphite showed that the concentration was l.2x10⁵ (C-14 atoms/mg graphite). Based on this value, the extraction system blank was evaluated from results obtained with natural graphite and copper oxide, without quartz sample, to be (2-6)x10⁵ (C-14 atoms). AMS measurement of quartz samples showed that C-14 concentration raging form 5.7 x10⁴ to 1.5 x10⁵ (C-14 atoms /g quartz) and the erosion rate of roughly 1.8x10⁻³ cm/y, which was evaluated from analysis of Be-10 and Al-26., 石英試料(阿武隈高原北部において、表層から地下70cm（120 g/㎠）までの深さから採取したもの)に、天然石墨と酸化銅を添加して1900℃で加熱した。この加熱処理により、溶融石英からC-14を抽出し、また天然石墨を酸化銅で酸化し炭素の担体ガスに転換した。抽出処理において、モダンカーボンによる汚染を減らすために、天然石墨を担体ガスの前駆体として使用した。この理由は、天然石墨中はC-14含有量が無視でき、保管中に大気の炭酸ガスによって汚染をうけにくいためである。AMS測定の結果、天然石墨のC-14濃度は1.2x10⁵(atmos/mg)であり、この値を基に算出した溶融炉のC-14のバックグランドは(2~6)x10⁵個となった。石英試料中のC-14濃度は5.7x10⁴~1.5x10⁵(atoms/g)となり、削剥速度はBe-1OおよびAl-26の分析から得られた1.8x10⁻³ cm/yとおおよそ一致した。, 第22回名古屋大学年代測定総合研究センターシンポジウム平成21(2009)年度報告},
 pages = {46--52},
 title = {石英中のC-14の測定},
 volume = {21},
 year = {2010}
}