| Project/Area Number |
12440076
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | RIKEN |
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Principal Investigator |
WADA Michiharu RIKEN, Atomic Physics Lab. , Senior Researcher, 原子物理研究室, 先任研究員 (50240560)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAI Youichi RIKEN, Atomic Physics Lab. , Senior Researcher, 原子物理研究室, 先任研究員 (30260194)
KOJIMA Takao m. RIKEN, Atomic Physics Lab. , Senior Researcher, 原子物理研究室, 先任研究員 (90211896)
YAMAZAKI Yasunori University of Tokyo, Physics Institute, Ptofessor, 総合文化, 教授 (30114903)
KATAYAMA Ichiro KEK, Institute of Particle and Nuclear Studies, Professor, 素粒子原子核研究所, 教授 (30028237)
OKADA Kunihiro Sophia University, Department of Physics, Research Associate, 理工学部, 助手 (90311993)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 2001: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2000: ¥10,400,000 (Direct Cost: ¥10,400,000)
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| Keywords | rf ion guide / RI-Beam / ion trap / gas catcher / イオンガイド / フラグメントセパレータ |
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| Research Abstract |
The projectile fragment separator (RIPS) at the RIKEN accelerator facility provides a wide variety of RI-beams with less restrictions on their chemical property or lifetime limit. The beam energy and quality is, however, not adequate for low-energy beam experiments, in particular for trapping experiments. We have been working on technical developments toward precision atomic spectroscopy of trapped RI-ions by slowing down the energetic RI-beams provided by the RIPS using a large gas-catcher cell and an rf ion guide system. The high energy beam (〜GeV) is first passed through a degrader and then stopped and thermalized in a large He gas cell (〜100 Torr). The high ionization potential of He guaranties that most ions end up in the singly ionized state. Subsequently, using the ion charge as a handle, we apply dc electric fields to pull the RI-ions to a cathode electrode located at an exit hole, while rf-fields at the cathode electrode keep them away from the surface of the electrode. We tested two types of cathode electrodes and named them rf-funnel and rf-carpet depend on their structure. On-line tests of the rf ion-guide system have been performed at the RIPS facility which provides a 70 MeV/u Li-8 ion beam with a typical intensity of -10^6 atoms/s. An overall efficiency of 1% was obtained so far, when the beam intensity was weak. A decrease of the efficiency was observed as increasing the beam intensity. This effect was partially compensated by decreasing the impurities by employing a cold trap in the cell.
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