A numerical study, employing the particle coderinga[Plasma Phys.23, 521 (1981)], of two ion rings that merge with each other due to their mutual magnetic attraction is presented. It is shown that an ion ring with closed magnetic field lines (field reversed) can be formed by merging two weaker non‐field‐reversed rings. A rough calculation shows that there is an optimal plasma conductivity &sgr;≊c2/4&pgr;aR&OHgr;&zgr;1/2(aandRare the respective axial width and major radius of the ring, &OHgr; is the ion cyclotron frequency in the external magnetic field, and &zgr; is the field reversal factor of the weaker ring) for which most of the energy of mutual magnetic attraction between the rings is dissipated during the process of merging.