  We propose and demonstrate a new method for Doppler cooling trapped-ion
crystals where the distribution of micromotion amplitudes may be large and
uneven. The technique uses pulses of Doppler cooling light synchronized with
the trap RF that selectively target ions when their velocity is near a node,
leading to more uniform cooling across a crystal by a single tone of cooling
light. We lay out a theoretical framework that describes where this technique
is practical, and provide a simple experimental demonstration.
