2024-03-28T22:08:54Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00026308
2023-01-16T04:16:51Z
879:1183:2103:2107
Status and Applications of a Tandetron AMS System at Nagoya University in 2017
名古屋大学タンデトロンAMS14Cシステムの現状と利用(2017)
中村, 俊夫
79196
南, 雅代
79197
増田, 公明
79198
小田, 寛貴
79199
池田, 晃子
79200
栗田, 直幸
79201
山根, 雅子
79202
西田, 真砂美
79203
藤沢, 純平
79204
方, 雨婷
79205
徳丸, 誠
79206
木田, 梨沙子
79207
酢屋, 徳啓
79208
北川, 浩之
79209
Nakamura, Toshio
79210
Minami, Masayo
79211
Masuda, Kimiaki
79212
Oda, Hirotaka
79213
Ikeda, Akiko
79214
Kurita, Naoyuki
79215
Yamane, Masako
79216
Nishida, Masami
79217
Fujisawa, Junpei
79218
Fang, Yuting
79219
Tokumaru, Makoto
79220
Kida, Risako
79221
Suya, Tokunori
79222
Kitagawa, Hiroyuki
79223
accelerator mass spectrometry
radiocarbon
high-voltage spark
beam-correction magnet
high-voltage control system
beam transmission of tandem accelerator
2018-03-31
An AMS system (Model 4130-AMS) dedicated to 14C measurements, built by High Voltage Engineering (HVE), B.V., the Netherlands, was delivered to Nagoya University in 1996/97. Acceptance tests of its performance on carbon-isotope-ratio measurements were completed in January of 1999, and routine measurements began in mid-2000. The number of targets measured was 330, 1430, 2077, 1003, 1,979, 1679, 1772, 1115, 1339, 866, 1300, 1701, 1449, 1634, 1351, 1741, 1156, 466 and 900 in each year from 1999 to 2017, respectively, and total number of targets measured by the end of December 2017 is 25,287. We briefly describe the maintenance processes of the AMS system in the year of 2017. The Tandetron AMS system at Nagoya University has encountered several problems in 2017. They are; (1) two big sparks seriously damaged the solid state RF driver for the high voltage generation, and the AMS system could not supply the high voltage of 2.5 MV used for 14C measurements. We replaced a damaged coil at the final part of the high-voltage power supply unit with a new coil; (2) a power supply unit for loading electrical current to correctly adjust the current for the recombinator magnet was in trouble. A resistance unit located at the end of current supply circuit was burnt out. We replaced it to a new one; (3) after a high-voltage spark, we could not apply high voltage to the accelerator. A control circuit board of supplying high voltage was checked and it was found out that the electrical board B-5-41-205-0001 was out of work. We replace the board to one repaired previously; (4) During the usual measurement of a graphite target, 12C3+, 13C3+ and 14C3+ decreased gradually in the last half of its measurement time of 30 minutes. The plus ion beam intensity of 13C3+ decreased from 200nA to 5nA in ten minutes, without any changes on its target current (corresponding to 13C- current). We first checked all the parameter values of the power supplies to the AMS system, but we could not find any changes from their nominal values. We finally concluded that something wrong has happened inside the accelerator tank, and decided to open the tank after 5 years of previously opening the tank. Owing to these problems, we can process only 900 graphite targets in 2017. In 2017, we also have carried out some application programs of 14C measurements at Nagoya University. Some of the results are included in this Proceedings volume.
departmental bulletin paper
名古屋大学宇宙地球環境研究所
2018-03-31
名古屋大学年代測定研究
2
79
87
jpn