Fig. 1. (a) The raw image of Al⁺ with O\begin{document}$ _2 $\end{document} as carrier gas recorded at 193 nm and (b) nearly a quarter part of the enlarged image, in which the inner ring (region A) has a lower velocity and the angular distribution tends to be isotropic compared to that of the outer region (region B). The polarization direction of the laser is shown in the figure.

Fig. 2. Speed distributions of Al⁺ ions obtained from the integration of images over (a) an entire range of 0\begin{document}$ ^{\circ} $\end{document}-360\begin{document}$ ^{\circ} $\end{document} and (b) the small angular range of 0\begin{document}$ ^{\circ} $\end{document}\begin{document}$ \pm $\end{document}5\begin{document}$ ^{\circ} $\end{document} for a better resolution.

Fig. 3. Total kinetic energy distribution of Al/Al⁺+O converted from FIG. 2(b).

Fig. 4. Angular distributions of Al⁺ ions in (a) Al(\begin{document}$ ^2 $\end{document}P\begin{document}$ _ \rm{u} $\end{document})+O(\begin{document}$ ^3 $\end{document}P\begin{document}$ _ \rm{g} $\end{document}) channel and (b) Al⁺(\begin{document}$ ^1 $\end{document}S\begin{document}$ _ \rm{g} $\end{document})+O(\begin{document}$ ^3 $\end{document}P\begin{document}$ _ \rm{g} $\end{document}) channel obtained from AlO(\begin{document}$ v $\end{document} = 0, 1, and 2), respectively.