The critical state of thin SQUID arrays

The current and field profiles are calculated for a thin SQUID array as functions of the normalized maximum Josephson current imax and the perpendicularly applied field. In comparison with the SQUID array treated earlier without considering demagnetizing effects. the same transition from the vortex state to the critical state is found with increasing imax, but, the rational normalized critical current ic is now multiplied by a prefactor varying with the array dimensions. These results further confirm the intergranular critical state in granular bulk high-Tc. superconductors to arise at sufficiently large junction currents and provide a case where theoretical results can be checked by experiments.