Line vortex pinning and their spacing in a 3D ordered Josephson medium

The method of solution of the system of finite-difference equations for interacting line vortices in a three-dimensional ordered Josephson medium is proposed. The critical values of the pinning parameter at which two vortices keep their given spacing and the maximum pinning forces for different configurations are calculated. It is shown that the pinning force decreases near the parallel vortices and increases near the antiparallel ones.