| Project/Area Number |
16K05005
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
General applied physics
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
Hiroyuki Miyamaru 大阪府立大学, 工学(系)研究科(研究院), 教授 (80243187)
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2018: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
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| Keywords | BNCT / 中性子 / 窒化ホウ素 / 中性子計測 / MAPMT / 放射線計測 / シンチレーター / 光ファイバー / ZnS(Ag) / 線量計測 / 加速器 / 線量測定 |
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| Outline of Final Research Achievements |
Boron neutron capture therapy (BNCT) using accelerators is now widely spread as a new cancer treatment. But the neutrons produced by the accelerators have high energetic part and it is harmful components. Therefore, it is necessary to measure and evaluate the therapeutic neutron flux for each energy component. In the present study, we have developed a new type of neutron spectrometer to measure the neutron flux in real time by separating the thermal, epi-thermal and fast components. A new dosimetry method was proposed and its basic principle and effectiveness were confirmed. Boron nitride was used as a filter to separate the energy components of neutrons. Based on the neutron detection yield which is a function of the filter thickness, the component separation was performed analytically, and it was found that both methods of gradient decent and the Bayesian estimation were effective.
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| Academic Significance and Societal Importance of the Research Achievements |
近年、先進がん治療であるホウ素中性子捕捉療法に使われる中性子だが、中性子は電荷を持たないため、そのエネルギーを直接測定することは通常は困難である。本研究では中性子吸収材の厚みを変化させながら測定したデータに対して、勾配降下法やベイズ推定法を用いて解析することでエネルギー成分の弁別を可能にした。また、治療用の中性子束が極めて大線量なため、光ファイバーによる伝送、ガンマ線に感度が小さい薄板状シンチレーターの開発など、困難な大線量場の計測を可能にする工夫が多く含まれており中性子計測技術の発展に貢献した。
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