  Experimental results for the reflection coefficient of shock-compressed dense
Xenon plasmas at pressures of 1.6 - 17 GPa and temperatures around 30 000 K
using a laser beam with \lambda = 1.06 10^-6 m are compared with calculations
based on different theoretical approaches to the dynamical collision frequency.
It is found that a reasonable description can be given assuming a spatial
electron density profile corresponding to a finite width of the shock wave
front of about $2 10^-6 m.
