We have studied laser collimation of a chromium atomic beam using a tr
ansverse polarization gradient cooling scheme. We present detailed mea
surements of the angular distribution of atoms on the beam axis, over
a broad range of laser intensities and detunings, including those that
produce significant excitation, and observe collimation angles as sma
ll as 0.16+/-0.01 mrad (50% quantile). We compare our results with exi
sting calculations based on assumptions of steady-state conditions and
low excited-state population.