Excitation of the 3p state of neon by high-resolution electron impact

We have measured the electron-impact excitation function for the excited state of neon at energies from threshold (18.966 eV) to about 20.6 eV. The measurements have been carried out with a high-resolution (20 meV) electron spectrometer by detecting the yield of 5852 Å radiation, emitted in the decay of the state to the level (the transition in Paschen notation), as a function of the incident energy. The excitation function has also been calculated using a modified version of the Breit--Pauli R -matrix codes of Berrington et al in a 31-state calculation. The agreement between experiment and theory is encouraging, particularly with regard to the presence of a number of negative-ion resonances. Conclusions regarding the previous classifications of these resonances are drawn.