Excitation of helium by protons and multiply charged ions: Analytic form of scaled cross sections

The cross sections for excitation of n1L (L=S,P,D) states of He from its ground state in collisions with protons and multiply charged ions are presented in scaled and closed analytic form. The scaling includes all the relevant dynamic and atomic parameters (collision energy, transition energy, ionic charge) and is based on the existing theoretical models for the process at low and high energies. A few parameters in the analytic scaled excitation cross sections are determined from the experimental data. The scaled sections for transitions from excited states are also briefly discussed. (author). 12 refs, 6 figs