量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum and Radiological Science and Technology.
Thank you very much for using our website. On the 11th of March 2019, this site was moved from our own network server to the JAIRO Cloud network server. If you previously bookmarked this site, that bookmark will no longer work. We would be grateful if you could bookmark the website again. Thank you very much for your understanding and cooperation.
To determine biological effectiveness of mixed LET heavy-ion particles, a rotating range shifter was designed, and measured the physical characteristics. The shifter made from 4 mm thick brass blade having different duty cycle produced a dual-peak Bragg curve (DBP: dual Bragg-peak). The range of the 2nd peak was shifted to up stream 21.4 mm as water equivalent depth from the original peak. From 135 MeV/u carbon beam or 500 MeV/u iron beams with adequate binary filter, we could obtain (estimated) 190 and 27.8 keV/um or 1000 and 300 keV/um DBP beams that calculated from the residual range of each peak. Chinese hamster V79 cells were irradiated at the position with the rotating range shifter, fixed blade, or without any shifters. The survival curve with the rotating range shifter showed higher radiobiological effect compared with an expected response for carbon beam, but lower effects for iron beams, that calculated from the survival curves with fixed blade and without shifters under an assumption
重粒子線治療の最適化のための生物学研究-VI；混合ビームの生物効果
