Depth concentration profile of cesium in fullerene absorbent studied by synchrotron X-ray photoelectron spectroscopy

Sekiguchi, Tetsuhiro  ; Yokoyama, Keiichi  ; Uozumi, Yuki*; Yano, Masahiro   ; Asaoka, Hidehito  ; Suzuki, Shinichi; Yaita, Tsuyoshi

For nuclear transmutation of cesium-135 (Cs-135), which is long-lived fission product, we are developing selective absorbent which takes only Cs atom in, but does not CsI. In this study, absorbing property of Cs atom or CsI into fullerene (C) solid has been investigated using synchrotron-based angle-dependent X-ray photoelectron spectroscopy (ARXPS). It was found that Cs penetrates into C deep bulk. In contrast, CsI does not diffuse into bulk, although CsI over-layer was formed on the shallow surface. Furthermore, XPS spectra were measured as a function of Ar-sputtering time in order to know Cs concentration profiles in further deep region. Results showed that Cs penetrates into deep region of several hundreds .