Vacuum-ultraviolet continuum emission from HeH

Vacuum-ultraviolet continuous emission spectra have been acquired from dense, cold helium gas in the pressure of solid hydrogen during excitation by a 6.5-MeV proton beam. The emission has been identified as the $D^2$ ${\Sigma }^{+}$→X ${}_{}{}^2{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$ radiative dissociation of HeH, based on theoretical potential curves and the qualitative similarities of the continuum to discrete bands previously observed with this experimental technique.