Resonant rotational excitation of H2by electron impact

Abstract

By using an electron impact spectrometer with a greatly improved energy resolution it has been possible to study the appearance of H₂^- resonances in the energy range 11.0 to 12.25 eV in reactions which lead to specific rotational-vibrational states of the final H₂ molecule. Rotational excitations having Delta J=-2 (i.e. 2 to 0, 3 to 1), Delta J=0 (i.e. 0 to 0, 1 to 1,2 to 2, etc), Delta J=+2 (i.e. 1 to 3,3 to 5), and Delta J=+4 (i.e. 1 to 5), accompanied by vibrational excitations Delta v=0, 1, 2, 4, 6 and 8 have been studied. Two series of resonances (series a and c) have been seen, and their symmetry classifications have been established as ² Sigma _g⁺ and ² Pi _u respectively.