hbox badness with line breaking in tables and use of \raggedright

Question

I am hunting for hbox badnesses in my document at the moment and have some problems in resolving issues with a table using tabularx. As suggested in this thread I am using \raggedright to relax the typesetting problems due to line breaking. But however, when I do so in the last column, it produces some errors indicating a missplaced \noalign. Now I am a little confused, what the actual error is, I am doing here.

The \mbox in the MWE are used to prevent unwanted line breaking.

MWE:

\documentclass{letter}
\usepackage{tabularx}
\begin{document}
\begin{tabularx}{\textwidth}{X|X|X|X|X|X}
    \raggedright TIC & \raggedright \mbox{absolute} shot number & \raggedright recorded proton spectra & \raggedright modulated proton spectra & \raggedright highest cut-off energy (MeV) & \raggedright avg. \mbox{cut-off} energy (MeV) \\
    \hline $2\times 10^{-13}$  & 150 & 88.6\% & 31.6\% & 14.1 & $6.8 \pm 1.8$
\end{tabularx}
\end{document}

This is the result I get, if I don't set the last column header to raggedright, but producing underfull boxes:

And this is the way it looks, when setting the last column header to \raggedright:

Obviously this leads to some misinterpretation of where the linebreak has to be.

Answer 1

You need to use \tabularnewline to end the table row, or use \raggedright\arraybackslash to reset \\ to its tabular meaning, as \raggedright redefines \\ to do a ragged text line end.

You can use >{\raggedright\arraybackslash}X to save adding this in every cell explicitly.