2005 Fiscal Year Final Research Report Summary
Study on Fragment Production by Protons and Neutrons and its Effects to the Materials and Living Bodies
| Project/Area Number |
15360499
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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 |
Nuclear engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
BABA Mamoru TOHOKU UNIVERSITY, CYCLOTRON AND RADIOISOTOPE CENTER, PROFESSOR, サイクロトロン・ラジオアイソトープセンター, 教授 (20005466)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Yukinobu KYUSHU UNIVERSITY, INTERDISCIPLINARY GRADUATE SCHOOL OF ENGINEERING SCIENCE, ADVANCED ENERFGY ENGINEERING, ASSOCIATE PROFESSOR, 大学院・総合理工学研究院, 助教授 (30210959)
SANAMI Toshiya HIGH ENRGY ACCELERATOR RESAERCH ORGANIZATION, RADIATION SCIENCE CENTER, RESEARCH ASSOCIATE, 放射線科学センター, 助手 (90321538)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Fragment / Nucleons-induced / Bragg Curve Spectrometer / Energy-TOF method / Energy spectrum / C, Al, Si / 70 MeV protons / 65 MeV neutrons |
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| Research Abstract |
Soft errors and hard errors of semiconductor devices by radiations are of serious problems in mode information society. To trace the problem, we carried out the followings : (1) Development of experimental technique to measure the fragment production cross sections for ten's of MeV nucleons, (2) acquisition of systematic experimental data of important nuclides, and (3) evaluation of theoretical models for fragment production and its influence on the materials and living bodies.
1. For fragment measurement, we adopted 1) a Bragg curve Counter (BCC) and 2) energy-TOF(E-TOF method), and realized the measurement of fragments for protons and neutrons by improving the method with respect to signal-to-noise ratio, dynamic range and efficiency. The neutron induced-fragment production data is the first one in the world We extended the pulse-height range up to about twice by a)lowering the threshold energy of fragment identification by newly adopting the information on the anode-cathode time-diff
… More
erence (corresponding to range), and b)developing a method to estimate the original energy of fragment which penetrated the sensitive volume of BCC. The data for neutrons were upgraded by the development of BCC with a segmented anode of concentric circle and according improvement in fragment identification as well as background reduction. For low energy particles which are difficult to measure with the BCC technique, we constructed and adopted an E-TOF spectrometer employing a micro-channel plates and semiconductor detectors.
2. Employing devices developed, we conducted measurement of fragment production for 70 MeV protons and 65 MeV neutrons. Fragment data were obtained from helium to oxygen at 0-deg for neutrons and at 30, 60, 90, 135-deg for protons.
3. We compared our experimental fragment spectra with theoretical calculations and evaluations for fragment production to evaluate their validities and problems. Generally, the models showed serious disagreement with experiment and should be improved greatly. Less
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Research Products
(11 results)
