R&D on mercury target for spallation neutron source to improve the durability under high power operation, 5; Application of anomaly detection and diagnosis for structural integrity evaluation of a mercury target vessel

Saruta, Koichi   ; Murata, Atsushi*; Maeno, Koki*; Wakui, Takashi  ; Naoe, Takashi   ; Kogawa, Hiroyuki  ; Li, Y.*; Teshigawara, Makoto   ; Haga, Katsuhiro  ; Futakawa, Masatoshi  

In the spallation neutron source at the J-PARC, the mercury target vessel incorporates several countermeasures against cavitation erosion, which reduces the vessel's lifetime. Anomaly detection and diagnosis of the vessel will play an increasingly important role in long-term operation under increased proton beam powers. A laser Doppler vibrometer and a microphone are employed in an attempt to evaluate the correlation of anomalies with the vibration and sound that are excited on the vessel by the incident proton beams, generated by the mercury flow running through the double-wall structure, and caused by the microbubble generator. An overview of the development plan of anomaly detection and diagnosis for the target vessel using vibration and sound measurement is presented and discussed based on preliminary results obtained in water-loop experiments.