AE technique is expected to be an useful monitoring and diagnosing technique for superconducting magnet. Already, it has been proven that AE technique is a powerful tool to identify and understand causes of magnet quenches. In the paper, the developement of AE technology as it is applied to superconducting magnet is reviewed. Future directions of research are also discussed.
Origins of AE are investigated. It is shown that wire motions and other mechanical disturbances are dominant AE sources and that flux motion, except flux jumping, produces no descernable AE signals. Papers concerning AE sources are reviewed and the results are compared.
The monitoring superconducting magnet by its acoustic emission has been found effective during the operation of the magnet. We have observed various AE from the magnet. Sources of AE generation are roughly classified and ordered according to their strength of AE, i.e., fracture of conductor destruction, conductor movement, fracture of support material, magnetization of conductor and S/N transition. Here, acoustic emission during the magnetization of the conductor and the magnet are mainly explained by showing the experimental results and theoretical discussions. The AE due to magnetization has been found to be related to the magnetic flux movement by Lorentz force.