Project/Area Number |
02452027
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
核・宇宙線・素粒子
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Research Institution | Kyushu University |
Principal Investigator |
MORINOBU Shunpei (1991) Kyushu Univ., Fac. Sci., Professor, 理学部, 教授 (50016078)
黒柳 登喜大 (1990) 九州大学, 理学部, 教授 (70037159)
|
Co-Investigator(Kenkyū-buntansha) |
INOUE Hikaru Hiroshima Univ., Fac., Sci., Associate Prof., 理学部, 助教授 (30028170)
MITARAI Shiro Kyushu Univ., Fac., Sci., Assistant, 理学部, 助手 (00108648)
|
Project Period (FY) |
1990 – 1991
|
Project Status |
Completed (Fiscal Year 1991)
|
Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥7,100,000 (Direct Cost: ¥7,100,000)
|
Keywords | Nuclear Structure / Nuclear Deformation / Multiplicity of Charged Particle / Rotational Band of Nucleus / Crystal Ball / In-beam Spectroscopy / Fusion Reaction Induced by Heavy Ion / Silicon Ball / γ線多重度 |
Research Abstract |
In the early stage of this project, a silicon detector array (Si Ball) which had proved to be quite powerful in the identifications and selections of the reaction channels in heavy ion fusion reaction was improved to stand the high duty use at high beam currents. The combined system of NORDBALL and the improved Si Ball brought about a dramatic progress in the spectroscopic studies of the new deformed region of A=80 90. As a result, new level structures of nucleides of ^<87>Mo, ^<87>Nb, ^<85>Nb, ^<82>Y, ^<81>Y, ^<82>Zr and ^<82>Sr including highly excited states have been established and the analysis for the nuclear properties have been carried out. The deformation of nuclei in this region grows with the nucleon number toward Z and N = 40. The isotones of N = 46 were found to lie the border between spherical and deformed nucleus regions, and the nuclei of N=45 and 46 seem to be strongly deformed at highly excited high-spin states. These experimental results have been compared with the results of cranking model calculation. Besides the above mentioned studies in Japan-NBI collaboration, lots of experiments have been carried out at the tandem accelerator laboratory of Kyushu University to clarify the properties of low-lying and ground states of the nuclei in the A = 80 -90 region. The fruitful outputs including a systematic discovery of new isotopes not only gave complementary information for the high spin states at high excitation but also led to the development of a new effective method of collecting thorough spectroscopic knowledge of these nuclei.
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