Study on effects of energetic ion irradiation in GdO-doped CeO by means of synchrotron radiation X-ray spectroscopy

放射光X線分析によるガドリニアをドープしたセリアのイオン照射効果研究

田原 佑規*; 清水 浩貴*; 石川 法人   ; 岡本 芳浩  ; 堀 史説*; 松井 利之*; 岩瀬 彰宏*

Tahara, Yuki*; Shimizu, Hirotaka*; Ishikawa, Norito; Okamoto, Yoshihiro; Hori, Fuminobu*; Matsui, Toshiyuki*; Iwase, Akihiro*

核燃料のガドリニアのドープ効果と核分裂生成物元素の高エネルギー照射効果を、セリアを使い調べた。照射実験では、200MeVのXeイオンを照射し、照射効果を広域X線吸収微細構造(EXAFS)法を使いその影響を評価した。照射によって、第1近接Ce-OとCe-Ceの距離が長くなり、その傾向はガドリニアをドープしたもので顕著になった。デバイワーラー因子も照射により大きくなった。ただし、ガドリニアのドープによるデバイワーラー因子への影響は小さかった。

To study the effects of GdO-doping and the irradiation with high energy fission products in the nuclear fuels (UO), GdO-doped CeO pellets were irradiated with 200 MeV Xe ions. Effects of GdO-doping and the ion irradiation were estimated by using Extended X-ray Absorption Fine Structure (EXAFS) measurement. The interatomic distances between each Ce and the first nearest O atoms, and Ce and the second nearest Ce atoms increase by the irradiation and the effect of the ion irradiation on the atomic distances is more pronounced for higher amounts of dopant. The Debye-Waller factors for Ce-O and Ce-Ce pairs increase with increasing the amount of GdO dopant. These results suggest that the lattice binding energy is weakened by GdO-doping. The Debye-Waller factors increase also by the irradiation. The effect of ion irradiation on the Debye-Waller factors, however, becomes smaller for higher amounts of dopant.