Abstract
The propagation of normal region in a superconducting coil was first studied theoretically and experimentally by Steckly. And the theory has been supported by some subsequent experimental works.
A stabilized superconducting coil, such as one made of Cu clad Nb-Ti wire, however, has not yet been investigated in detail on its behavior of protected and unprotected superconducting small coils would with Cu clad Nb-Ti wire. The appearance of coil resistance was mainly investigated of two coils, one of which was divided into five sections of winding. In each coil, the time dependence of the coil resistance was found to be different from Steckly's theory. A new mechanism of the growth of normal region was proposed to explain this phenomenon.
The temperature rise at some points in the coilafter quenching was also measured with Cu-constantan theromo couples inserted into intersections of the windings.
