Abstract

Collisions of ultracold trapped atoms ( T< 1mK) have opened a new field of atomic collisions with abundant opportunities for theory and experiments. Photo-associative ionization (PAI) in sodium atoms has been the first two-body collision Studied in optical traps³. In this process two ground state Na atoms absorb two photons during the course of the collisional encounter. The first absorption at long range put the colliding system on an attractive C₃/R³ potential curve, and the two atoms begin to accelerate toward each other. A second absorption promotes the system to a doubly excited Na(3p)+Na(3p) potential curve from which the PAI process takes place at short range.

© 1993 Optical Society of America