Development of extremely high-temperature X-ray absorption fine structure measurement method for oxide samples

Since the severe accident at Fukushima Daiichi Nuclear Power Plant, there has been an interest in the properties of oxide fuels in their near-melting temperature range. X-ray absorption fine structure (XAFS) is an effective method for understanding the fine structure and chemical bonding state of a sample; however, high-temperature XAFS measurements performed to date have been limited to 2000 K. We have developed a method for XAFS measurements of high-melting oxides above 2000 K. This method utilizes resistance heating of tungsten and confines the sample within a 0.06 mm slit to enable transmission-type XAFS measurements. We successfully performed an XAFS test with yttria-stabilized zirconia loaded at the tip of the slit and heated to 3000 K.