  We describe and characterize a device for alkali vapor pressure modulation on
the 100ms timescale in a single-cell cold atom experiment. Its mechanism is
based on optimized heat conduction between a current-modulated alkali dispenser
and a heat sink at room temperature. We have studied both the short-term
behavior during individual pulses and the long-term pressure evolution in the
cell. The device combines fast trap loading and relatively long trap lifetime,
enabling high repetition rates in a very simple setup. These features make it
particularly suitable for portable atomic sensors.
