\begin{table}%t1
\caption{\label{energy_tab}Kinetic energy $E$ and reduced energy~$\varepsilon$ for H, He and~C impacting on a carbon atom.}
%\centering
\small	
\begin{tabular}{c c c c c}      
\hline\hline \noalign{\smallskip}
Projectile  &  $E$$^a$($v_{\rm p1}$)  &  $\varepsilon$$^b$($v_{\rm p1}$)  &  $E^{a}$($v_{\rm p2}$)  & $\varepsilon^{b}$($v_{\rm p2}$) \\
\hline	      
H    &   7.30  &   0.031  &   117.4  &   0.50  \\
He   &   29.4  &   0.048  &   469.7  &   0.76  \\
C    &   88.1  &   0.028  &   1409.  &   0.45  \\
\hline 
\end{tabular}
\tablefoot{\tablefoottext{a}{Kinetic energy in eV. The projectile velocities $v_{\rm p1}$~= 37.5~km~s$^{-1}$ and $v_{\rm p2}$~= 150~km~s$^{-1}$ are defined by the shock velocity~$v_{\rm   S}$ via the equation $v_{\rm p}$~= $\frac{3}{4}$~$v_{\rm S}$, with $v_{\rm S}$~= 50 and 200~km~s$^{-1}$ respectively.} \\
\tablefoottext{b}{Dimensionless, calculated from Eqs.~(\ref{eps_eq}) and~(\ref{aU_eq}).}}
\end{table}