Laser trapping of short-lived radioactive isotopes.

We describe an experiment which demonstrates the feasibility of trapping significant quantities of short-lived radioactive atoms with laser light. A thermal beam of 22.5 sec half-life [sup 21]Na atoms was produced on-line at the LBL 88[prime][prime] Cyclotron. After decelerating the beam using a Zeeman-tuned slowing technique we stored about 4[times]10[sup 3] [sup 21]Na atoms in a magneto-optical trap. The number of trapped atoms is large enough to be used in experimental studies of the beta decay of [sup 21]Na. The basic method can be adapted for other rare isotopes.