1990 Fiscal Year Final Research Report Summary
Systematic Study on the Complete Fusion of Light Heavy Ions
| Project/Area Number |
62460013
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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 |
核・宇宙線・素粒子
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
ARAI Eiichi Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Professor, 原子炉工学研究所, 教授 (50016846)
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| Co-Investigator(Kenkyū-buntansha) |
HATTORI Toshiyuki Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Associa, 原子炉工学研究所, 助教授 (50134648)
OGAWA Masao Tokyo Institute of Technology, Graduate School at Nagatsuda, Associate Professor, 大学院総合理工学研究科, 助教授 (60016863)
OGURI Yoshiyuki Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Associa, 原子炉工学研究所, 助手 (90160829)
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| Project Period (FY) |
1987 – 1989
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| Keywords | heavy ions / nuclear fusion reactions / evaporation residues / time of flight measurements / pulse height defects / analysis of material surface / Coulomb barrier |
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| Research Abstract |
Reaction cross sections were systematically measured around the Coulomb-barrier energy for complete fusion between projectile nuclei with A=10 - 35 and target nuclei with A=12 - 60 in order to investigate the effects of nuclear parameters such as deformation and excitation energy of the nuclei on the values of cross sections. The time of flight method (TOF) was adapted to detect evaporation residues from the fusion reactions. One of the reasons why the TOF method has been used to identify the particle mass is the big potential in the application to the microelectronics surface studies. The elastic recoil detection analysis (ERDA) is known as one of the promising methods in this new field.
A beam of heavy ions was generated by the Tokyo Institute of Technology Heavy-ion Linac (the official name of the system is Experimental Facility for Composite Irradiation). After we have verified the experimental setup by measuring some standard reactions, fusion reaction cross sections have been meas
… More
ured for the systems formed by the combination of targets nuclei ^<12,13>C and projectiles of ^<15>N and ^<16,18>O nuclei. The results have been compared with theoretical prediction from the programme CASCADE. Through the data analysis we have found out that in this mass and energy regime there exist only limited data for the correction of the pulse height defect (PHD) in the surface barrier detectors used in the present experiments. This was an essential hurdle for our TOF spectrometer.
We have started experimental studies on PHD to obtain reliable data for the present energy and mass region. The result is the published in the first reference. The next step is to continue the fusion reaction measurement, where we have studied the systems produced by projectiles of ^<16>O and ^<19>F and target nuclei of ^<54,56>Fe. We have observed in the measured cross sections rather large enhancement in the fusion reactions at incident energies below the Coulomb barrier. The theoretical analysis was performed by means of the programmed CCFUS. Agreement is very good. These results are published in the 2nd and 3rd references. As an application study we have recently obtained the first TOF ERDA results from the surface analysis of electronics materials such as Si wafers covered by a 10 nm TaO_x layer. Less
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