  We present progress towards a planned experiment on atomic tunneling of
ultra-cold Rb atoms. As a first step in this experiment we present a
realization of an improved form of "delta-kick cooling." By application of a
pulsed magnetic field, laser cooled Rb atoms are further cooled by a factor of
10 (in 1-D) over the temperature out of molasses. Temperatures below 700 nK are
observed. The technique can be used not only to cool without fundamental limit
(but conserving phase-space density), but also to focus atoms, and as a
spin-dependent probe.
