Study on depth profile of heavy ion irradiation effects in poly(tetrafluoroethylene-co-ethylene)

Poly(tetrafluoroethylene-co-ethylene)への重粒子線照射効果の深さ依存性

五輪 智子*; 塩津 智之*; 裏川 達也*; 岡 壽崇   ; 村上 健*; 大島 明博*; 濱 義昌*; 鷲尾 方一*

Gowa, Tomoko*; Shiotsu, Tomoyuki*; Urakawa, Tatsuya*; Oka, Toshitaka; Murakami, Takeshi*; Oshima, Akihiro*; Hama, Yoshimasa*; Washio, Masakazu*

高LET放射線である重粒子線をETFEに真空、及び大気中で照射した。ETFEに対する照射効果を重粒子線の進入深さの関数として評価した。重粒子線照射によって共役二重結合が生成し、その生成量分布はブラッグ曲線に非常によく似ていること、LETが高くなるほど、C=Cの二重結合の長さが長くなることがわかった。さらに、大気中照射においては、試料表面からの酸素分子の拡散により、C=O結合が増加することが明らかになった。

High linear energy transfer (LET) heavy ion beams were irradiated to poly(tetrafluoroethylene-co-ethylene) (ETFE) under vacuum and in air. The irradiation effects in ETFE as a function of the depth was precisely evaluated by analyzing each one of the films of the irradiation samples which were made of stacked ETFE films. It was indicated that conjugated double bonds would be generated by heavy ion beam irradiation, and their amounts should show the Bragg-curve-like distributions. Also, it was suggested that higher LET beams would induce radical formation in high density and longer conjugated C=C double bonds could be generated by the second-order reactions. Moreover, for irradiation samples in air, C=O was produced correlating to the yield of oxygen molecules diffusing from the sample surface.