Magnetic field dependence of the critical current in a granular s-wave   Superconductor
  The magnetic field dependences of the critical-current of a granular s-wave superconductor has been determined by considering the rectangular and circular junction model of an array of small superconducting particles which interacting by Josephson coupling through insulating barriers. We will show that in the case of circular model, the maximum critical current of the Josephson current is larger than that of rectangular model. 
E. Afsaneh and H. Yavari
cond-mat.supr-con