  In this paper, direct observation of micromotion for multiple ions in a
laser-cooled trapped ion crystal is discussed along with a novel measurement
technique for micromotion amplitude. Micromotion is directly observed using a
time-resolving, single-photon sensitive camera that provides both fluorescence
and position data for each ion on the nanosecond time scale. Micromotion
amplitude and phase for each ion in the crystal are measured, allowing this
method to be sensitive to tilts and shifts of the ion chain from the null of
the radiofrequency quadrupole potential in the linear trap. Spatial resolution
makes this micromotion detection technique suitable for complex ion
configurations, including two-dimensional geometries. It does not require any
additional equipment or laser beams, and the modulation of the cooling lasers
or trap voltages is not necessary for detection, as it is in other methods.
