An absorption spectrum of He2 in the VUV

Absorption profiles of He2 molecular bands blue shifted to the corresponding atomic resonance lines are reported. The absorption profiles are obtained from fluorescence excitation spectra of dense He1 gas. The strongest band is assigned to the transitions X 1Σ+g→D1Σ+u and F 1Π. The characteristic line shape allows the determination of the height of the barriers in the potential curves. The height of the barriers shows a simple dependence on the main quantum number, which is discussed in view of two limiting cases.