  We have studied a general technique for laser cooling a cloud of polarized
trapped atoms down to the Doppler temperature. A one-dimensional optical
molasses using polarized light cools the axial motional degree of freedom of
the atoms in the trap. Cooling of the radial degrees of freedom can be modelled
by reabsorption of scattered photons in the optically dense cloud. We present
experimental results for a cloud of chromium atoms in a magnetic trap. A simple
model based on rate equations shows quantitative agreement with the
experimental results. This scheme allows us to readily prepare a dense cloud of
atoms in a magnetic trap with ideal starting conditions for evaporative
cooling.
