  Attention is fixed on shells in toroidal nuclei in the intermediate mass
region using a toroidal single-particle potential. We find that there are
toroidal shells in the intermediate mass region with large single-particle
energy gaps at various nucleon numbers located at different toroidal
deformations characterized by the aspect ratios of toroidal major to minor
radius. These toroidal shells provide extra stability at various toroidal
deformations. Relative to a toroidal core, Bohr-Mottelson spin-aligning
particle-hole excitations may be constructed to occupy the lowest
single-particle Routhian energies to lead to toroidal high-spin isomers with
different spins. Furthermore, as a nucleon in a toroidal nucleus possesses a
vorticity quantum number, toroidal vortex nuclei may be constructed by making
particle-hole excitations in which nucleons of one type of vorticity are
promoted to populate un-occupied single-particle orbitals of the opposite
vorticity. Methods for producing toroidal high-spin isomers and toroidal vortex
nuclei are discussed.
