Study on optical sound measurement for the in-situ diagnostic system under high radiation environments

Murata, Atsushi*; Saruta, Koichi   ; Wakui, Takashi  ; Li, Y.*; Tsutsui, Kihei*; Futakawa, Masatoshi  

Vibration and sound have been used in diagnosis of mechanical structures in a variety of industries. Under high radiation environments, however, conventional electric sensors such as an accelerometer and a microphone are not suitable especially for in-situ diagnostic systems in nuclear reactors, spallation neutron source systems, etc. since electric signals become degraded by background radiation noise. In this study, the applicability of the optical sound measurement using an laser Doppler vibrometer was investigated through the comparison between fundamental experimental results and 3D FEM analyses (LS-DYNA) for the purpose of developing an in-situ diagnostic system of a mercury target.