@article{oai:nagoya.repo.nii.ac.jp:00018046, author = {中村, 俊夫 and 南, 雅代 and 小田, 寛貴 and 池田, 晃子 and 一木, 絵理 and 伊藤, 一充 and 宮田, 佳樹 and 箱崎, 真隆 and 太田, 友子 and 西田, 真砂美 and 池盛, 文数 and 城森, 由佳 and 加藤, ともみ and 早田, 葵 and 長谷, 和磨 and 冨山, 慎二 and Nakamura, Toshio and Minami, Masayo and Oda, Hirotaka and Ikeda, Akiko and Hitoki, Eri and Itoh, Kazumi and Hakozaki, Masataka and Miyata, Yoshiki and Ohta, Tomoko and Nishida, Masami and Ikemori, Kazufumi and Jyomori, Yuka and Kato, Tomomi and Soda, Aoi and Hase, Kazuma and Tomiyama, Shinji}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {An AMS system (Model 4130-AMS) dedicated to14C measurements, built by High Voltage Engineering Europe (HVEE), B.V., The Netherlands, was delivered to Nagoya University in 1996/97. Acceptance tests of its performance on carbon isotope measurements were completed in January of 1999, and routine measurements began in mid-2000. Since completion of the acceptance tests in early 1999, we have encountered a lot of troubles with the machine, particularly in 2002. Since the end of 2002, the machine has worked relatively well, expect for minor problems. The standard deviation (one sigma) of the 14C/12C ratio is around ±0.3% to ±0.4% (a bit larger than the uncertainty of about ±0.3% calculated from 14C counting statistics) and that of the corresponding 13C/12C ratio is ±0.03% to ±0.07% , as are tested for HOxII targets. The number of targets measured was 330, 1430, 2077, 1003, 1,979, 1679, 1772, 1115, 1339, 866, 1300, 1701, 1449, 1634 in each year from 1999 to 2012, respectively, and total number of targets measured by the end of 2012 is 19,674. The Tandetron AMS system worked well in the early half of 2012, with only minor failures. In September, a noise became large from the 12C-beam chopper, in the recombinator system, owing to the problem of a ferro-fluid-feedthrough, which had been used since June, 2008. We have replaced the ferro-fluid feedthrough to a new one. Soon after the chopper problem, the turbo molecular pump (TMP) in the recombinator system was damaged with the bearing of the rotating fan. We sent the pump to the supplier for repair. Because of the broken bearing, the rotating fan was seriously damaged, and we must purchase a new one. On 24th October, a large noise was generated from inside of the accelerator tank. We decided to open the tank and check the parts inside. The problem was also a bearing mounted in the power generator that supplies electric power to a terminal turbo-pump mounted inside the tank. We can get a new generator in a few weeks, because HVEE possessed one for spare by chance. We purchased it and replaced the damage generator on November. After tank opening, inner surfaces of the accelerator tank absorbed water in the atmosphere, we spent much time to remove water vapor from SF6 insulator gas. We had experienced twice of high voltage sparks, but no detectable damage occurred with the accelerator system. We could have restarted 14C measurements at around mid of December. Owing to these difficulties with the machine, the total number of graphite targets measured was 1634 in 2012, smaller in number than that in 2010 (1701), but a larger than in 2011 (1449)., 名古屋大学年代測定総合研究センターシンポジウム報告}, pages = {13--24}, title = {名古屋大学タンデトロンAMS14Cシステムの現状と利用(2012)}, volume = {24}, year = {2013} }