Neon 3p-excitation by proton impact (100 keV-1MeV): Cross sections and line polarization

The excitation of all ten levels of the neon 2p53p configuration by proton impact (100 keV- 1 MeV) has been investigated by the spectral analysis of photon emission. Absolute emission cross sections have been obtained by calibration with a standard light source. Cascade effects are shown to be very important especially in the case of J = 1 levels. For the 3p(1S0) level, which we studied additionally for electron impact excitation (100eV- 1 keV), our experimental cross sections are compared with the first Born approximation. Furthermore the polarization of sixteen 3p - 3s emission lines has been measured as a function of impact energy. The energy dependence of the line polarization is characterized by the J quantum numbers of the atomic states involved in the respective transition. An anomalous polarization of all lines originating from the decay of J = 1 levels has been found and is referred to dominant cascade effects. (orig.)