An Experimental Study on the Superconducting Coil Behaviors Using Electromagnetic Pulse Signals During Ramping

Measurement and the analysis are done for the pulse signals from magnetic sensors (search coils) near superconducting coils and voltage taps on the coils. The superconducting coils are arranged facing each other, and the magnetic sensors and the voltage taps are expected to detect the coil behavior (motion of the coils, motion of coil windings, and so on) as the pulse signals during the ramping up. One of the causes of the superconducting coil quenching is the occurrence of a small mechanical disturbance around the coil windings. Therefore, information about the coil behavior from these pulses should be useful to get a better understanding of the quenching phenomena. The results of the pulse analysis suggest that the signals can be classified into just two patterns. In addition, only one of them is observed from the signals just before all quenchings; these are supposed as signals of the trigger disturbance of quenching. This fact suggests that the disturbance which causes the quenching has a strong relationship with the specific motion of the coils.