Study of nuclear reaction model for precise estimation of secondary exposure in carbon-ion therapy

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H03522
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nuclear engineering
• Research Institution: Kyushu University
• Principal Investigator: Uozumi Yusuke 九州大学, 工学研究院, 准教授 (00232801)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 炭素線がん治療 / 原子核反応 / 二重微分断面積 / 原子核反応模型

Outline of Final Research Achievements

In heavy ion radiotherapy, carbon ions are used to attack cancers in the patient's body. During carbon ions travel in the body, they can undergo nuclear reactions with elements of body. It is known that the most reaction products appear along the primary beam direction. Since there are concerns about long-term late effects due to low dose exposure, highly accurate prediction of dose is required, and it is necessary to measure double-differential cross-section (DDX) data and develop a theoretical model.
We developed the experimental equipment and measured DDXs. Experiments were carried out at the Heavy Ion Medical Accelerator In Chiba (HIMAC). The energy of emitted particles was measured with two types of crystal spectrometers. The notable point is that high-energy particles are observed at large angles. This fact suggests that the high-energy heavy-ions can have a long range over the beam diameter.

Free Research Field

原子力

Academic Significance and Societal Importance of the Research Achievements

本研究の結果、炭素イオンによる多様な荷電粒子生成に関する原子核反応二重微分断面積データを測定する環境が整備されて、生体構成元素に対する二重微分断面積データを測定することが出来た。学術的には、新しいデータが得られ、その分析から未解決の問題が発見できたと期待される。理論的分析により炭素イオン反応に関する知見が深まり、高精度計算のための原子核反応模型の検討が大きく進展した。社会的には、大きな期待が持たれる小児がんの重粒子線がん治療において晩発効果の評価に要する低線量被ばく量を推定するための知見など基盤形成に向けてデータが整えられており、大きな意義がある。