  A theoretical model of one-body nuclear friction which was developed earlier,
namely the chaos-weighted wall formula, is applied to a dynamical description
of compound nuclear decay in the framework of the Langevin equation coupled
with statistical evaporation of light particles and photons. We have used both
the usual wall formula friction and its chaos-weighted version in the Langevin
equation to calculate the fission probability and prescission neutron
multiplicity for the compound nuclei $^{178}$W, $^{188}$Pt, $^{200}$Pb,
$^{213}$Fr, $^{224}$Th, and $^{251}$Es. We have also obtained the contributions
of the presaddle and postsaddle neutrons to the total prescission multiplicity.
A detailed analysis of our results leads us to conclude that the chaos-weighted
wall formula friction can adequately describe the fission dynamics in the
presaddle region. This friction, however, turns out to be too weak to describe
the postsaddle dynamics properly. This points to the need for a suitable
explanation for the enhanced neutron emission in the postsaddle stage of
nuclear fission.
