Density effect for the ionization loss of charged particles in various substances

The density-effect correction $\ensuremath{\delta}(\ensuremath{\beta})$ for the ionization energy loss of charged particles has been evaluated for 72 substances (34 metallic elements, 26 compounds, 11 gases, and liquid hydrogen), using up-to-date values of the mean excitation potential $I$ and of the atomic absorption edges $h{\ensuremath{\nu}}_{i}$, which were employed as input data for the general equations for $\ensuremath{\delta}(\ensuremath{\beta})$ previously derived by Sternheimer.