Response of aqueous dichromate and nanoclay dichromate gel dosimeters to carbon ion irradiation

7th International Conference on 3D Radiation Dosimetry

Maeyama, T.^1 ; Fukunishi, N.^1 ; Ishikawa, K.L.^2,3,4 ; Fukasaku, K.^2,5 ; Furuta, T.^7 ; Takagi, S.^2,6 ; Noda, S.^2,7 ; Himeno, R.^2,7 ; Fukuda, S.^8

RIKEN, Nishina Center for Accelerator-Based Science, Wako, Japan^1

RIKEN, Computational Science Research Program, Wako, Japan^2

University of Tokyo, Department of Nuclear Engineering and Management, Graduate School of Engineering, Tokyo, Japan^3

University of Tokyo, Photon Science Center, Graduate School of Engineering, Tokyo, Japan^4

Himon'ya Hospital, Department of Neurosurgery, Tokyo, Japan^5

University of Tokyo, Department of Mechanical Engineering, Graduate School of Engineering, Tokyo, Japan^6

RIKEN, Advanced Center for Computing and Communication, Wako, Japan^7

National Institute of Radiological Sciences, Research Center for Charged Particle Therapy, Chiba, Japan^8

关键词: Carbon ion beams;    Clay nanoparticles;    Dose depth distribution;    Efficiency degradation;    High linear energy transfers;    Product diffusion;    Radiation-induced;    Reaction mechanism;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012033/pdf
DOI  :  10.1088/1742-6596/444/1/012033

来源: IOP

【 摘 要 】

We have recently reported the significant reduction of radiation product diffusion by the incorporation of clay nanoparticles into dichromate gel (DCG) dosimeters. In this work, we investigate the influence of the nanoclay addition and gelation on the MRI R1(1/T1) image response of the dichromate dosimeter to the therapeutic carbon ion beam (12C6+290 MeV/u). The MRI R1distribution in the aqueous dichromate solution well reproduces physical dose-depth distribution with a high linear-energy-transfer (LET) efficiency. The nanoclay DCG dosimeters, on the other hand, exhibit composition-dependent LET efficiency degradation, while a sharp Bragg peak can still be detected. These results indicate that the nanocomposite gel addition may induce change in the radiation-induced reaction mechanism.