Detachment of very-low-energy electrons from H^{-}

High-resolution energy spectra of electrons detached from ${\mathrm{H}}^{-}$ and ${\mathrm{D}}^{-}$ upon collisions with He and Ar have been measured at and near ${\theta }_L=0\mathrm{}°$. The measurements reveal some structure previously unseen in the high-energy peak at $v_e=v_i$. This structure, along with changes in the spectra for ${\theta }_L>0\mathrm{}°$, leads to the assumption that the peak at $v_e=v_i$ is due to the superposition of a very sharp peak on a broader peak. This very sharp peak has been stripped from the data and transformed to the rest frame of the incident ion. The ejection probabilities for the very-low-energy group of electrons (≲ 0.10 eV) were found to possess forward-backward symmetry and to be insensitive to the target gas and velocity of the ion.