Absolute electron scattering cross sections for the 2S→2P transition in Zn+ using energy-loss and merged-beams methods

Using the electron energy-loss method in a merged electron-ion beams geometry absolute, cascade-free excitation cross sections have been measured for the resonance 2S→2P transition in Zn+. Measurements were carried out at electron energies of below threshold (threshold at 6.011 eV) to 40 eV. Results are in very good agreement with close-coupling calculations and, away from threshold, lie below absolute line-emission cross sections which include effects of cascade into the 2P state from higher levels