Transverse laser cooling of a metastable argon beam: Dependence on the interaction time

A pulsed metastable argon beam is transversely cooled in one dimension via the closed 4s[11/2]2o-4p[21/2]3 transition. A standing light wave, orthogonal to the atomic beam and located just at the source, provides the cooling. In all the measurements, the maximum electric field is equivalent to a Rabi frequency of ∼220 natural linewidths. The enhancement of the metastable atom flux is measured as a function of the interaction time with a time-of-flight technique. The dependence on the laser detuning is investigated and compared with theory.