Temperature and background field dependence of thermal stability in a compact MgB2 solenoid coil

A conduction cooled compact react and wind MgB2 solenoid magnet was tested for quench propagation and minimum quench energy MQE in a background field which allows to an extent a decoupling of the peak field in the windings from the conductor field performance. MQE and propagation data was taken in self field at 30, 30.5 and 31.5 K and at fields/temperatures of 1 T/25 K, 3 T/18 K and 5 T/10 K where the power law n-value characteristic was similar at n~30. At all temperatures and at low I/Ic quench propagated first through the insulating layers, in a radial direction, and at high I/Ic within the layer. The MQE values as a function of I/Ic are shown to consistently have non zero values as I? Ic which is characteristic of an analytical quench model that includes the n-value power law dissipation. At 30.5 K a sharp drop in MQE occurs along with the change in propagation direction. The analytical model is then exploited as 1D adiabatic, 3D infinite solenoid, and 3D with heat transfer at the boundary to explore the affect of dimensionality and conduction cooling on the propagation and MQE behavior