Excitation of the 4P11-nD21 lines of Zn atoms by monoenergetic electrons

The optical excitation functions (OEF) for three zinc spectral lines originating from the n1D2 levels (n=4-6) are presented. Fourteen structural features were revealed in the energy dependences of electron excitation cross-sections measured from the excitation threshold up to 18.5eV. The resonant features below the atomic ionization threshold are due to the decay of short-lived states of the negative Zn- ion. Above the ionization threshold the contributions from autoionizing states of the neutral atom are revealed. The obtained results help to understand in more detail the population processes of the levels under study