  We consider the production and detection of a sequential, down type quark via
the mode $p p \to b' {\bar b}' \to W^+ W^- t {\bar t} \to \ell \nu_{\ell} 8 j$
at the LHC, with the collision energy $\sqrt{s}=10$ TeV and the total
integrated luminosity around 1 fb$^{-1}$. We assume $m_{b'}=m_{t'}=600$ GeV. A
full reconstruction is employed and the signal and background discrimination is
studied within a neural network approach. Our results show that this mode can
make a useful contribution to the $b'$ search.
