  Materials containing hydrogen and high-Z ion species are used in a variety of
high energy density physics (HED) applications, and it becomes increasingly
important to investigate transport properties of these substances as they
become fully-ionized multispecies plasmas. In particular, of significant
practical interest, is the analysis of the plasma viscosity as it can determine
stability and turbulence properties of the HED system. It has been pointed out
by D. Ryutov [Phys. Plasmas 3, 4336 (1996)] that the presence of a substantial
amount of hydrogen in a multispecies plasma can significantly enhance its
viscosity. The present work reports on a detailed analysis of this effect and
the accurate calculation of the corresponding viscosity coefficient.
