苫小牧高専に出張中に嬉しいお知らせが参りました。先日のSOFT2022のFull PaperとしてFusion Engineering and Design誌に投稿した論文の受理通知です。
こちらは今年２月にPlasma and Fusion Research誌に受理された論文の続報で、引き続き核融合炉のダイバーター冷却管接合部の超音波検査に関するものです。前回の論文のものと比べるとより実際に近い試験体を用い、接合時に意図せず生じた剥離も検出できた、ということを報告したものです。
Title: High frequency ultrasonic inspection of the bonded interface between a divertor monoblock and a cooling pipe (ダイバーターモノブロックと冷却管の接合界面の高周波超音波検査）
Abstract: This study evaluated the applicability of a high-frequency ultrasonic test to the inspection of the bonded interfaces between a divertor monoblock and a cooling pipe. This study prepared a tungsten block bonded with 1 mm of oxygenfree copper and 1.5 mm-thick CuCrZr plates, which simplifies one of the fundamental designs of a divertor: a tungsten monoblock bonded with a cooling pipe with a copper interlayer. The samples were fabricated using a hightemperature vacuum furnace for diffusion bonding. A high-frequency ultrasonic immersion test using a 30 MHz probe was performed from the CuCrZr surface to simulate inspecting the interface from inside the pipe. Ultrasonic images obtained by the test were consistent with the actual bonding condition revealed by sectioning the samples; whether a flaw exists on the interface between CuCrZr and the oxygen-free copper or that between the oxygen-free copper
and tungsten was clearly distinguished. The results of this study also suggested the possibility of detecting the growth of crystal grains caused by improper bonding such as too high bonding temperature.