Intensity dependence of optical suppression in photoassociative ionization collisions in a sodium magneto-optic trap

We report the intensity dependence of photoassociative ionization collisions in a sodium magneto-optic trap (MOT). A suppressor beam with frequency tuned 600 MHz to the blue of the MOT trapping transition reduces the rate constant of the inelastic process by as much as a factor of 20 at an intensity of 8 W ${\mathrm{cm}}^{\mathrm{-}2}$. A comparison with theory shows good agreement.