Statistical diagnosis method of conductor motions in superconducting magnets to predict their quench performance

Premature training quenches are usually caused by the transient energy rele ased within the magnet coil as it is energised, Two distinct varieties of d isturbances exist, They are thought to be electrical and mechanical in orig in. The first type of disturbance comes from non-uniform current distributi on in superconducting cables whereas the second one usually originates from conductor motions or micro-fractures of insulating materials under the act ion of Lorentz forces. All of these mechanical events produce in general a rapid variation of the voltages in the so-called quench antennas and across the magnet coil, called spikes. A statistical method to treat the spatial localisation and the time occurrence of spikes will be presented. It allows identification of the mechanical weak points in the magnet without need to increase the current to provoke a quench. The prediction of the quench lev el from detailed analysis of the spike statistics can be expected.