  We propose a new geometry of optical lattice for cold atoms, namely a lattice
made of a 1D stack of dark ring traps. It is obtained through the interference
pattern of a standard Gaussian beam with a counter-propagating hollow beam
obtained using a setup with two conical lenses. The traps of the resulting
lattice are characterized by a high confinement and a filling rate much larger
than unity, even if loaded with cold atoms from a MOT. We have implemented this
system experimentally, and obtained a lattice of ring traps populated with
typically 40 atoms per site with a life time of 30 ms. Applications in
statistical physics, quantum computing and Bose-Einstein condensate dynamics
are conceivable.
