\begin{table}%t2
\caption{\label{iteration_number}Number of iterations needed to reproduce the exact
  solution with a relative error about $10^{-3}$ at line center, with the
  parameters of the magnetic field in Cols.~2 and~3 the same as
  in Figs.~\ref{fig.determ} and~\ref{fig.micro}.}
%\centering
 \small
\begin{tabular}{ c  c  c  c  }
 \hline\hline
\noalign{\smallskip}
 & {Rayleigh }& {Deterministic}& {Micro-turbulent}\\
 $T$ & $N_k$  & $N_k$ & $N_k$ \\
\noalign{\smallskip}
 \hline
\noalign{\smallskip}
$10^{-2}$ &3& 3& 3\\ 
$10^{-1}$ & 4& 4& 4\\
$1$ & 7 & 7 & 5\\
$10$ & 16 & 16& 9 \\
$10^2$ & 12& 11& 4 \\
$10^3$ & 7 & 6 & 5 \\
$10^4$ & 7 & 7 &5\\
$10^6$ & 8 & 7& 5 \\
$10^8$ & 8& 7 & 5 \\
 \hline 
\end{tabular}
\end{table}