| Project/Area Number |
05452030
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
NAKASHIMA Takao KYUSHU UNIVERSITY PHYSICS,ASSOCIATE PROFESSOR, 理学部, 助教授 (90037200)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Hiroyuki KYUSHU UNIVERSITY PHYSICS,RESEARCH ASSOCIATE, 理学部, 助手 (70172434)
SUGIMITSU Tuyoshi KYUSHU UNIVERSITY PHYSICS,RESEARCH ASSOCIATE, 理学部, 助手 (70037216)
TAKAOKA Nobuo KYUSHU UNIVERSITY PHYSICS,PROFESSOR, 理学部, 教授 (40028171)
MORINOBU Shunpei KYUSHU UNIVERSITY PHYSICS,PROFESSOR, 理学部, 教授 (50016078)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1994: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1993: ¥5,200,000 (Direct Cost: ¥5,200,000)
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| Keywords | Acceleraror Mass Specrometry (AMS) / antarctic meteorite / terrestrial age / tandem accelerator / chlorine 36 / long life radio-isotope / magnetic field modulation / beam bunching / ビームバンチング / 南極〓石 / タンデム型加速器 / 質量走査式AMS |
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| Research Abstract |
In the study of terrestrial ages of the antarctic meteorites, it is known that the contents of ^<36>Cl in the meteorites give a decisive information. An accelerator mass spectrometry (AMS) system was constructed at Kyushu University tandem accelerator laboratory in order to facilitate the ^<36>Cl measurement.
1. development of AMS techniques
(1) We proposed a new technique for the application of a conventional tandem accelerator facility to AMS.In this method, an extremely weak sample beam (^<36>Cl) and a reference beam (^<35>Cl or ^<37>Cl) are accelerated and transported on the same orbit alternately at a rate of several cycles per second by modulating synchronously the fields of all the deflector magnets on the beam transport line (from the ion source to the detector). A test of the method was performed and an enough capability of this method was confirmed.
(2) For further discrimination of the background ions on the detector, it was noted that the addition of a time structure to the sample beam and its use in the ion detection are important. For this purpose, a beam bunching device at the tandem injection port was designed and is now in test operation.
(3) As a particle identification detector, a prototype multi-collector ion chamber (MCIC) was constructed and tested. It was practically used in the AMS test experiment.
(4) To enhance the capability of the AMS system further, an advanced mass analyzer system and a gas-stripper cell for the tandem accelerator were designed. The former is now under construction and the latter is in R&D stage.
2. To avoid contamination of the isobar nulide ^<36>S in the sample preparation, and to insure a perfect collection of the ^<36>Cl nuclide in an appropriate form for the Cs-sputtering ion source, the chemical treatment techniques were developed
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