MAGNETIC SELF-FIELD ENTRY INTO A CURRENT-CARRYING TYPE-II SUPERCONDUCTOR - III - GENERAL CRITERION OF PENETRATION FOR AN EXTERNAL-FIELD OF ARBITRARY DIRECTION

The first magnetic-flux penetration into a current-carrying cylindrica l type-II superconductor subjected to an external magnetic field is co nsidered in the frame of the London approximation. The lower transvers e critical field as well as critical field of the first vortex nucleat ion at the surface are evaluated on the basis of an exact solution for a vortex of arbitrary flat configuration. Taken together with the pre vious consideration of the parallel magnetic-field penetration in a cu rrent-carrying superconductor [Phys. Rev. B 49, 6950 (1994) and B 51, 3686 (1995)] the above results allow us to formulate the general crite rium for the first flux entry in the current-carrying samples of arbit rary transverse size subjected to an external field of arbitrary direc tion.