Abstract
Persistent Current Switch (PCS) is one of the important part of persistent current mode magnet system. The PCS has some degradation: it quenches at far below the critical current. Magnet system is restricted by the PCS quench. This paper studies the characteristics of PCS wound by a thinner CuNi matrix conductor such as 0.3mm in diameter for various magnetic field. It is obtained that its quench currents decrease with current sweep rate. In order to explain this dependence of current sweep rate, following instability model is developed: self-field AC losses increase PCS winding temperature thus PCS is quenched when current reaches its critical current determined by PCS's temperature. Numerical calculation on the model was performed and its result agreed with the experiment data.
