  We demonstrate a method to enhance the atom loading rate of a ytterbium (Yb)
magneto-optic trap (MOT) operating on the 556 nm ${^1S}_0 \rightarrow {^3P}_1$
intercombination transition (narrow linewidth $\Gamma_g = 2\pi \times 182$
kHz). Following traditional Zeeman slowing of an atomic beam near the 399 nm
${^1S}_0 \rightarrow {^1P}_1$ transition (broad linewidth $\Gamma_p = 2\pi
\times 29 $ MHz), two laser beams in a crossed-beam geometry, frequency tuned
near the same transition, provide additional slowing immediately prior to the
MOT. Using this technique, we observe an improvement by a factor of 6 in the
atom loading rate of a narrow-line Yb MOT. The relative simplicity and
generality of this approach make it readily adoptable to other experiments
involving narrow-line MOTs. We also present a numerical simulation of this
two-stage slowing process which shows good agreement with the observed
dependence on experimental parameters, and use it to assess potential
improvements to the method.
