@article{oai:nagoya.repo.nii.ac.jp:00011317,
 author = {中村, 俊夫 and Nakamura, Toshio and 中井, 信之 and Nakai, Nobuyuki and 古川, 路明 and Furukawa, Michiaki},
 journal = {名古屋大学加速器質量分析計業績報告書},
 month = {Mar},
 note = {A Tandetron accelerator mass spectrometer, constructed by the General Ionex Corporation, Mass., USA, has been installed at Nagoya University in 1982,to measure ^<14>C. The spectrometer has been used to measure ^<14>C concentrations of natural samples, as well as ^<14>C ages of geological and archeological samples. The Tandetron spectrometer measures ^<14>C/^<13>C ratios of carbon prepared from carbonaceous samples. The ratio of a young samples (^<14>C ages younger than several thousand years old) is routinely measured with a precision of ±1%, using a C-Ag mixture target containing only 2-5 mg of carbon, in a measurement lasting about 4 hours. Errors for older samples become larger, because of the smaller number of ^<14>C counts. The ^<14>C background level of the spectrometer, estimated by using old natural graphite, it about 3x10^<-16> in ^<14>C/^<12>C ratio. The Tandetron spectrometer has been applied to measure ^<14>C concentrations, Δ^<14>C, of annual rings (1945-1983) from a Kiso hinoki tree (Japanese Cypress), to investigate the annual Δ^<14>C variation of the atmospheric CO_2 ; the cause of variation could be addition of ^<14>C produced by nuclear weapon tests in late 1950's to early 1960's. The ^<14>C concentrations in pine needles, collected at the Higashiyama Campus of Nagoya University, have also been measured since 1983. The results in our ^<14>C measurement of pine needles are described in the present study, focusing on the annual changes in Δ<14>C values of the atmoshperic CO_2,and on the effect upon ^<14>C concentrations for pine needles of a local ^<14>CO_2 emission from incineration of radioactive organic solvent wastes containing ^<14>C, which have been produced by biochemical experiments with ^<14>C tracer, at the Radioisotope Center in the Higashiyama Campus of Nagoya University.},
 pages = {104--112},
 title = {名古屋大学東山キャンパス内の松葉の<14>^C濃度測定},
 volume = {2},
 year = {1991}
}