1993 Fiscal Year Final Research Report Summary
Theoretical study of the scattering of unstable nuclei and the synthesis of superheavy elements
| Project/Area Number |
04640280
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
核・宇宙線・素粒子
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
TAKIGAWA Noboru Tohoku Univ.Fac.of Sciences, Assitant Profressor, 理学部, 助教授 (00125600)
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| Co-Investigator(Kenkyū-buntansha) |
SAGAWA Hiroyuki 会津大学, 総合数理センター, 教授 (50178589)
SHINOZUKA Tsutomu 東北大学, サイクロトロンラジオアイソトープセンター, 助手 (10134066)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Heavy-ion collisions / Unstable nucleus / Halo nucleus / Heavy-ion fusion reactions / Fission / Transport phenomena / Superheavy elements / Quantum tunneling |
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| Research Abstract |
This research project aimed at exploring characteristics of heavy-ion collisions induced by unstable nuclei, especially by halo nuclei, and at finding a new way to synthesize superheavy elements. The structure of unstable nuclei and quantum tunneling in multi-dimensional systems were also studied as closely related subjects. The main achievements are as follows. 1. We studied the effect of projectile berak-up on the heavy-ion fusion reactions induced by a halo nucleus, and showed that one can still expect a larger fusion cross section for a halo nucleus than for the other isotopes at energies below the Coulomb barrier, though the projectile break-up moderates the large enhancement of the fusion cross section suggested in one of our previous papers for the collisions of a halo nucleus. 2. We showed that the differential cross section of the elastic scattering in medium energy heavy-ion collisions has a steeper fall off at angles where the so called far-side component dominates if a halo nucleus is used as the projectile. 3. We studied multi-nucleon transfer neactions in deep inelastic heavy-ion collisions based on a transport theory, and found that much larger number of neutrons are exchanged than protons if a halo nucleus is used as the projectile. 4. We showed that the tranverse momentum distribution of the projectile fragments in medium energy heavy-ion collisions gets narrower by reflectiong the reaction mechanism. 5. We studied the effects of environments on the tunneling rate of a macroscoic variable, and showed the importahce of a mass renormalization in the cases, where the environments have slightly shorter time scale than that of the tunneling process. Also, we developed a method, the method of dynamical norm factor, to treat non adiabatic effects in macroscopic quantum tunneling, and demonstrated its numerical accuracy by a few model calculations. Using this method, we analyzed the fission of ^<234>U, and showed that the coupling to a nuclear intrins
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