  New model of the pinning potential barrier in multi-layered HTc
superconductors has been presented, basing on geometrical approach to the
capturing interaction of pancake type vortices with nano-scale defects. Using
this model the transport current flow phenomena in these materials, especially
current-voltage characteristics and critical current density, have been
considered. Details of theoretical analysis are given, including derivation of
basic mathematical equations describing the potential barrier in the function
of transport current density and initial position of captured pancake vortex.
Computer simulation has been performed then of influence of transport current
amplitude on potential barrier height for various sizes of pinning centers and
initial pancake vortex position as well as influence of fast neutrons
irradiation on critical current of HTc layered superconductor.
