- To determine the magnetic field inside a superconductor, we have measured the distribution of the ac magnetic field in a narrow gap between two BSCCO superconducting cylinders with a set of Hall probes. Numerical simulations showed a close agreement between the magnetic field distributions inside the superconductor and the gap. Bean’s model was used for setting the current density distribution inside the superconductor. It was found that at low currents, the field distribution inside the superconductors could be described by Bean’s model. Marked difference observed at higher currents can be explained by flux creep and flux flow. © 2004 American Institute of Physics.