1997 Fiscal Year Final Research Report Summary
Nuclear Okorokov effect of heavy ions with relativistic energy
| Project/Area Number |
07404019
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物理学一般
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KOMAKI Ken-ichiro The University of Tokyo, Graduate School of Arts and Sciences, Professor, 大学院・総合文化研究科, 教授 (40012447)
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| Co-Investigator(Kenkyū-buntansha) |
MURAKAMI Takashi National Institute of Radiological Sciences, Senior Researcher, 放射線医学総合研究所, 主任研究官 (20166250)
AZUMA Toshiyuki The University of Tokyo, Graduate School of Arts and Sciences, Research Associat, 大学院・総合文化研究科, 助手 (70212529)
YAMAZAKI Yasunori The University of Tokyo, Graduate School of Arts and Sciences, Professor, 大学院・総合文化研究科, 教授 (30114903)
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| Project Period (FY) |
1995 – 1997
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| Keywords | channeling / heavy ion / Okorokov effect / nuclear excitation / resonant coherent excitation / relativistic energy |
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| Research Abstract |
Channeling ions have a possibility to be excited in the internal levels by a periodic potential of a crystal. It is called Resonant Coherent Excitation (PCE). The condition of RCE in nuclear levels is satisfied with relativistic heavy ions supplied by HIMAC.
A channeling experiment in a relativistic energy region requires a beam with extremely small angular divergence. We have developed a parallel beam, and observed the reductions of the energy deposition and the angular spread of channeling ions under several channeling conditions. channeling ions under several channeling conditions.
We have succeeded in observing the atomic RCE from 1s to n=2 states with 390MeV/u Ar^<17+> ions planar channeled in a Si crystal, by measuring the charge state distribution after transmission through the crystal. Under several RCE conditions, the fraction of survived Ar^<17+> ions was observed to decrease drastically. We also measured the energy deposition of channeling ions adopting a totally depleted silicon detector as a target crystal. The energy deposition of the plannar channeling ion is closely related to the trajectory in the crystal, and provides the information of the position dependent crystal field. The resonance profiles are well explained by the L・S interaction and the Stark effect originated in the crystal field.
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