\begin{table}%t4
%\centering
\par
\caption{\label{tab:beam1}Key polarisation parameters of the LFI beams.}
\begin{tabular}{ccrrrrrrrrr}
\hline \hline \noalign{\smallskip}
Feed & Band  & \multicolumn{2}{c}{Side arm} & \multicolumn{2}{c}{Main arm} 
& \multicolumn{5}{c}{Difference}\\
&& $\eta_{\rm s}$\tablefootmark{a} & $\delta_{\rm s}$\tablefootmark{a} & 
$\eta_{\rm m}$\tablefootmark{a} & $\delta_{\rm m}$\tablefootmark{a}
& $\bar{\eta}$\tablefootmark{a} & $\bar{\delta}$\tablefootmark{a}    
& $\langle{\cal M}_{QI}\rangle /\langle{\cal M}_{II}\rangle$\tablefootmark{b} 
& Max(${\cal M}_{QI}$)\tablefootmark{c} & Max(${\cal M}_{QU}$)\tablefootmark{c}\\ 
LFI- && $10^{-3}$ & \degr & $10^{-3}$ & \degr & $10^{-3}$ & \degr & 
$10^{-3}$ & \%   & \% \\ 
\hline
18 & & 1.91 & $ 0.23$ & 2.03 & $ 0.23$ & 1.97 & $ 0.23$ & $-$0.42 & $-$0.82 & $  1.75$ \\
19 & & 1.33 & $ 0.09$ & 1.46 & $ 0.09$ & 1.40 & $ 0.09$ & $-$0.30 & $-$0.75 & $  1.19$ \\
20 & \multirow{2}{*}{70~GHz} & 1.06 & $-$0.02 & 1.15 & $-$0.02 & 1.11 & $-$0.02 & $-$0.15 & $-$0.43 & $-$1.11 \\
21 & & 1.05 & $ 0.02$ & 1.11 & $ 0.02$ & 1.08 & $ 0.02$ & $-$$0.07$ & 
$-$0.31 & $  1.14$ \\
22 & & 1.33 & $-$0.09 & 1.46 & $-$0.09 & 1.39 & $-$$0.09$ & $ -$$0.29$ & 
$-$$0.73$ & $-$$1.22$ \\
23 & & 1.91 & $-$$ 0.33$ & 2.02 & $-$$0.33$ & 1.96 & $-$$0.33$ & $-$$0.34$ & $-$$0.77$ & $-$$2.04$ \\
        & & & & & & & \\
24 & & 1.84 & $ 0.00$ & 1.70 & $ 0.00$ & 1.77 & 0.00 & $0.27$ & $1.43$ & $  1.05$ \\
25 & 44~GHz & 4.58 & $-$$0.35$ & 4.46 & $-$$0.35$ & 4.52 & $-$$0.35$ & $  0.03$ & $ -$$2.14$ & $ -$$5.30$ \\
26 & & 4.58 & $ 0.35$ & 4.45 & $ 0.35$ & 4.52 & $ 0.35$ & $  0.02$ & $ -$$2.16$ & $  5.32$ \\
        & & & & & & & \\
27 & \multirow{2}{*}{30~GHz} & 2.19 & $-$$0.18$ & 2.07 & $-$$0.18$ & 2.13 & $-$$0.18$ & $  0.06$ & $  0.75$ & $ -$$1.87$ \\
28 & & 2.19 & $ 0.18$ & 2.07 & $ 0.18$ & 2.13 & $ 0.18$ & $  0.05$ & $  0.76$ & $  1.86$ \\
\hline
\end{tabular}
\tablefoot{All values are derived from beam models calculated assuming the
adopted flight model telescope geometry (RFFM), evaluated at the nominal
band-centre frequencies. 
\tablefoottext{a}{beam-averaged cross-polar leakage $\eta$ and  rotation $\delta$;}
\tablefoottext{b}{beam-averaged forward polconversion as a fraction of 
the integrated gain;} 
\tablefoottext{c}{absolute maximum values of the 
leakage for $I$ and $U_{\rm H}$ into $Q_{\rm H}$.}}\vspace*{2.5mm}
\end{table}