Coincidences between D(2S) and ${\mathrm{D}}^{+}$ fragments resulting from the bombardment of ${\mathrm{D}}_2$ with 100-eV electrons have been observed. A significant source of these coincidences is believed to be the 2s ${\mathrm{\sigma }}_{\mathit{g}}$ state of ${\mathrm{D}}_2^{+}$. The potential energy of the state in the Franck-Condon region was constructed from the time-of-flight distribution of these fragments.

• Received 11 December 1989

DOI:https://doi.org/10.1103/PhysRevA.42.6909