抄録
An acoustic emission (AE) from the superconducting magnet system provides a new method for monitoring the operating condition of the magnet. From our experimental results, we are able to utilize the acoustic emission for the prediction of the “Magnet Quench.”
The signal-to-noise ratio of AE transducers at liquid helium temperature has been found to be about 18dB higher than that at room temperature.
All the way from cooling down to the running of the magnet, we can monitor the whole system of both superconducting magnets and cryostats. From more detailed analysis, the acoustic signal is affected by electro-magnetic induction noise, and further, we are able to identify the acoustic emission of the superconducting magnet from that of the liquid helium shower, because of so much difference of the wave form and frequency spectrum.
For theoretical discussion, we have introduced an elastic medium model for the superconducting magnet to explain some stages of different acoustic emissions.
