Dissociative excitation of the B$^2\Sigma^{+}_{1/2}$ states of mercury monohalides by electron impact

An investigation was made of the process of excitation of HgCl$_2$, HgBr$_2$, and HgI$_2$ by electron impact producing B$^2\Sigma^{+}_{1/2}$ states of HgCl$^*$, HgBr$^*$, and HgI$^*$. The maximum values of the cross sections for dissociative excitation were found at low electron energies; the values of these cross sections were $\sigma=(6\pm3)\times 10^{-18}$, $(7.5\pm3)\cdot 10^{-17}$ см$^2$, and $(1.2\pm0,6)\cdot 10^{-17}$ cm$^2$ for HgCl$^*$, HgBr$^*$, and HgI$^*$, respectively. The role of such dissociative excitation in lasing was analyzed.