Development of an optical trap as an ultra-sensitive analytical tool

The use of an optical trap for the quantitative detection of small numbers of radioactive atoms is featured. Presently under construction is a system consisting of a high-efficiency magneto-optical trap (MOT) coupled to a mass separator. Mass-separated samples will be implanted into a thin platinum foil, subsequently released from the foil by heating, and resonantly trapped in the MOT. The number of atoms in the trap will be quantitatively deduced from the amplitude of the fluorescence signal. Measurements for different isotopes are planned by appropriately shifting the trapping and repumping laser frequencies of the optical trap. Our initial investigations will concentrate on the determination of trace amounts of {sup 135}Cs and {sup 137}Cs