Pinning of linear vortices and possible distances between them in a 3D ordered Josephson medium with a nonzero structural factor

On the basis of the fluxoid quantization conditions, we derive a system of equations describing the current configuration of two interacting linear vortices in a 3D ordered Josephson medium in the entire range of possible values of structural factor $b$. The axes of these vortices are located in the middle row of an infinite strip with a width comprising 13 meshes. We propose a method for solving this system, which makes it possible to calculate the current configurations exactly. The critical values of pinning parameter $I_d$ are calculated, for which two linear vortices can still be kept at a distance of $d$ meshes between their centers in the entire range of possible values of parameter $b$. The formula describing the $I_d(b)$ dependences for various values of d is derived. The dependences of the maximal pinning force $F$ on parameter $I$ for various values of $b$ are analyzed. It is shown that for the same value of $I$, larger values of $b$ correspond to larger maximal pinning forces.