A Protected 100-kG Superconducting Magnet

Superconducting wire made from heavily cold-worked ductile niobium-titanium wire shows much less degradation in solenoids than does the corresponding widely used niobium-zirconium alloy. The origin of this behavior is discussed in terms of flux jumping and the differences in metallurgical properties of the two alloy systems. The superior niobium-titanium alloy has been used in the inner sections of a 100 000-G solenoid which has been driven normal repeatedly without damage. Details of design, construction, and operation of this solenoid are discussed with particular reference to critical rate of excitation under flux creep conditions. The normalization properties of the solenoid are analyzed in terms of the thermal propagation model, and the voltage rise and temperature maximum are estimated from this model.