Fitting parameters ai of the fifth-order polynomial alpha (T_{e}) = sum ^5_{i=0} a_i T_e^i and scaling parameters E0 to reproduce the scaled PRC for Sn4 + through Sn13 + ions

Table 3. Fitting parameters ai of the fifth-order polynomial \alpha (T_{e}) = \sum ^5_{i=0} a_i T_e^i and scaling parameters E0 to reproduce the scaled PRC for Sn4 + through Sn13 + ions. The numbers in square brackets are powers of 10 to be multiplied with the preceding numbers, respectively. Abstract Electron-impact single-ionization cross sections of Snq + ions in charge states q = 4–13 with 4d[10 − (q − 4)] outer-shell configurations have been studied in the energy range from the corresponding thresholds up to 1000 eV. Absolute cross sections and fine-step energy-scan data have been measured employing the crossed-beams technique. Contributions of different ionization mechanisms have been analysed by comparing the experimental data with calculations employing the configuration-averaged distorted wave approximation. Ionization plasma rate coefficients inferred from the experimental data are also presented.