Development of diagnostic technique for structure filled with liquid metal using acoustic vibration

为了评估结构内表面的损伤，通过使用非接触和远程控制的测量技术，超声波波形和损伤量之间的关系被澄清。找出了检测微小损伤的最佳测量条件。由于超声波在含有液体的结构中传播时会受到液体的影响，因此在超声波测量中要考虑液体的影响。考虑到上述结果，开发了基于激光多普勒振动计的测量系统，并且可以以足够的精度测量质子束引起的振动，以监测汞靶容器。该测量系统可作为极端环境下使用的仪器的监测系统。

In order to estimate the damage on the inner surface of the structure, relationships between ultrasonic waveform and the amount of damage was clarified by using the contactless and remote controlled measuring technique. The optimal measurement conditions for detecting minute damage were found out. Because the ultrasonic wave propagating in the structure which includes the liquid was influenced the liquid, the influence was taken into account in the ultrasonic measurement. In consideration of the above result, the measuring system based on the laser Doppler vibrometer was developed and the vibration due to proton beams could be measured with sufficient accuracy to monitor the mercury target vessel. This measuring system can be applied as the monitoring system for the apparatus used under the extreme environment.