Results of the analysis of excited primary-ion-beam admixtures possibly present in the experiment

Table 1. Results of the analysis of excited primary-ion-beam admixtures possibly present in the experiment. The calculations were performed using the Cowan code [27]. The estimated fractions are the coefficients kE obtained from fitting equation (3) to the experimental data. Calculated excitation energies are given in column 4. The experimentally obtained ionization threshold energies (T.E.), T.E. taken from NIST Atomic Spectra Database [28] and T.E. calculated within the configuration-averaged approximation are provided in columns 5, 6 and 7, respectively. The estimated excited-levels' lifetimes and flight times of ions between the source and the interaction region are provided in the last two columns, respectively. 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.