  A numerical study of dynamos in rotating convecting plane layers is presented
which focuses on magnetic energies and dissipation rates, and the generation of
mean fields (where the mean is taken over horizontal planes). The scaling of
the magnetic energy with the flux Rayleigh number is different from the scaling
proposed in spherical shells, whereas the same dependence of the magnetic
dissipation length on the magnetic Reynolds number is found for the two
geometries. Dynamos both with and without mean field exist in rapidly rotating
convecting plane layers.
