  We demonstrate the feasibility of generation of quasi-stable
counter-propagating solitonic structures in an atomic Bose-Einstein condensate
confined in a realistic toroidal geometry, and identify optimal parameter
regimes for their experimental observation. Using density engineering we
numerically identify distinct regimes of motion of the emerging macroscopic
excitations, including both solitonic motion along the azimuthal ring
direction, such that structures remain visible after multiple collisions even
in the presence of thermal fluctuations, and snaking instabilities leading to
the decay of the excitations into vortical structures. Our analysis, which
considers both mean field effects and fluctuations, is based on the ring trap
geometry of Murray et al. Phys. Rev. A 88 053615 2013.
