Figure 1
Illustration: Alan Stonebraker

Figure 1: (Top to bottom) Atoms are captured and cooled to a temperature of ∼10μK by intersecting laser beams in a suitably arranged magnetic field. Another laser photoionizes the cooled atomic cloud. The resulting plasma expands (shown as a series of false-color electron spatial distribution plots) as a result of electron pressure, but overall the plasma remains neutrally charged.