Ionisation of phosphorus, arsenic, antimony, and bismuth by electron impact
Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica, 2829-516 Caparica, Portugal
2 Centro de Física Atómica da Universidade de Lisboa, avenue Prof. Gama Pinto 2, 1649-003 Lisboa, Portugal
Revised: 7 February 2008
Published online: 9 April 2008
Total ionization cross sections of neutral phosphorus, arsenic, antimony, and bismuth atoms by electron impact are reported and compared to the only available experimental results by Freund et al. [Phys. Rev. A 41, 3575 (1990)]. These calculations take into account the possibilities that some target atoms used in the experiments were in metastable states close to the ground state, the excitation-autoionization of nsnp4 excited states may be substantial, and the ions produced in experiments may be in excited, low-lying metastable states. The cross sections for direct ionization calculations are based on the BEB model by Kim and Rudd [Phys. Rev. A 50, 3954 (1994)]. Plane-wave Born cross sections scaled by the method developed by Kim [Phys. Rev. A 64, 3954 032713 (2001)] are used to determine the contributions from excitation-autoionization. The combination of the BEB model and the scaled Born cross sections is in agreement with the experimental data by Freund et al. These theoretical data are useful to experimentalists and can be used to complete data tables needed for plasma or astrophysical studies.
PACS: 34.80.Dp – Atomic excitation and ionization by electron impact / 34.80.Kw – Electron-ion scattering; excitation and ionization
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008