Magnetic Ring Stores Cold Atoms

Researchers at Georgia Institute of Technology in Atlanta have demonstrated a magnetic storage ring for the control of ⁸⁷Rb atoms. The device, called the Nevatron, may find application as an interferometric gyroscope for aircraft guidance or as a source for continuous-wave "atom lasers."

The researchers guide clouds of 3-µK atoms from a magneto-optic trap to the ring using a pair of copper wires that are separated by 4 mm at the trap and by 840 µm at the storage ring. The 2-cm-diameter ring also comprises two wires, separated by 840 µm and carrying a current of 8 A.

In the initial experiments, laser-induced fluorescence images of the atoms indicated that the trap supported up to seven revolutions of the cloud. Modifications to the apparatus should boost its performance by 100 times, enabling it to trap atoms for up to 20 seconds.