Time-frequency distribution of acoustic emission signals induced from a rotating NbTi superconducting winding

Quench tests were conducted using the time-frequency distribution of acoustic emission signals enabling a NbTi superconducting winding cooled in liquid helium to rotate. Acoustic emission converters were used for data acquisition for voltages in the superconducting winding. A comparison of the acoustic emission signals during a quench propagation with those of a non-quench case was performed to investigate the acoustic emission components resulting from only the quench propagation.