Rotational Excitation of H2 by Slow Electrons in a Beam Experiment

Rotational excitation and de-excitation ${J}_{f}\ensuremath{-}{J}_{i}=\ifmmode\pm\else\textpm\fi{}2$, ${J}_{i}=0,\ensuremath{\cdots},3$, of ${\mathrm{H}}_{2}$ by slow electrons with and without the simultaneous excitation of one vibrational quantum has been measured. The absolute total cross section for pure rotational excitation $J=3\ensuremath{\leftarrow}1$ in the energy range 1-10 eV is presented. The measurements of angular dependences indicate $s$-, $p$-, and $d$-wave scattering.