Microscopic evaluation of the absolute fluence distribution of a large-area uniform ion beam using the track-etching technique

トラックエッチング技術を用いた大面積均一ビームの絶対的なフルエンス分布の微視的評価

喜多村 茜; 八巻 徹也; 百合 庸介; 澤田 真一; 湯山 貴裕

Kitamura, Akane; Yamaki, Tetsuya; Yuri, Yosuke; Sawada, Shinichi; Yuyama, Takahiro

The uniform-beam formation/irradiation system has been developed at TIARA. For the evaluation of the beam uniformity, the relative intensity distribution is obtained from the optical density change of a radiochromic film. However, the absolute fluence distribution cannot be estimated easily and precisely by the radiochromic film based on radiation-induced coloration. In this study, we microscopically evaluated the particle fluence distribution using the track-etching technique, which involves irradiation of a polymer with energetic heavy ions and chemical-etching of the resultant tracks. Relative standard deviation (RSD) value for the microscopic fluence distribution of the uniform beam on the PET film was agreed well with that determined by the radiochromic film. The uniform intensity distribution was realized in our uniform-beam formation system microscopically.