Abstract

Recent developments in laser cooling and trapping of neutral atoms has opened the new field of atomic collisions at ultracold temperatures (<1 mK). This subject offers many new challenges for both theory and experiment. The standard concept of a collision breaks down owing to optical pumping and spontaneous emission over the long time and distance scales of the “collision.” We correct and generalize the model offered by Gallagher and Pritchard for trap-loss processes involving collisions of ground and excited alkali atoms. In general, trap-loss processes are those that impart sufficient kinetic energy to the atoms that they can escape the optical trap in which the collision occurs.

© 1991 Optical Society of America