MAGNETIC FLUX DIFFUSION INTO LONG TYPE-I SUPERCONDUCTING CYLINDERS: AN EXPERIMENTAL STUDY.

We have measured the total time required for the penetration of magnetic flux into a cylindrical specimen of pure indium, a Type-I superconductor, when an overcritical magnetic field is suddenly applied. Whereas previously reported measurements covered small excess fields, our measurements extend over magnetic fields up to 15 times the critical field and are in reasonably good agreement with the generalized theory recently proposed by Gauthier and Rochon.