Translational spectroscopy of electron impact dissociation of HF by doppler profile measurements of Balmer-α emission

The Doppler profiles of the Balmer-α emission by electron impact on HF have been investigated through varying the electron impact energy by using an etalon-grating monochromator with a high resolving power. The spectral profiles of the Balmer-α emission consist of three components, which indicates that there are three kinds of precursors leading to H*(3) contributing to the Balmer-α emission. The average kinetic energy of H*(3) is obtained for each component. From discussions on the precursors of H*(3) and their dissociation processes, the observed profiles have been ascribed to the dissociation of Rydberg states (≈18 eV), doubly excited states (≈23 eV) and inner shell excited states (≈40 eV).