Abstract
A method for detecting particles and measuring velocities in an atomic beam is described with experimental results, using high power optical pumping with a tunable c.w. dye laser. Simultaneous detection and velocity analysis is achieved by detecting the resonance fluorescence and measuring the Doppler shift of the excitation frequency. Expressions for the detection efficiency (being around unity) and the velocity resolution (being approximately 60 m s-1, independent of nu ) are given and verified experimentally for Na atoms.