  We demonstrate an atom trap geometry for 87Rb which is capable of producing
ultra high atom densities. Reradiation forces, which usually limit high
densities, can be avoided in dark spontaneous-force optical traps (dark SPOTs)
by sheltering atoms from intense trapping light. Here we demonstrate a dynamic
implementation of a dark SPOT, resulting in an increase in atom density by
almost two orders of magnitude up to 1.3x10^12cm-3. Holographic control of the
trapping beams and dynamic switching between MOT and dark SPOT configuration
allows us to optimise the trapping geometry. We have identified the ideal size
of the dark core to be six times larger than the MOT. Our method also avoids
unwanted heating so that we reach a record phase-space density for a MOT.
