Theoretical Investigations Of (e,2e) Ionization Of Electron Impact Potassium Atom

In this paper, three Coulomb wave (namely 3C model) and dynamic screening three Coulomb wave approximate method (namely DS3C model) have been applied to calculate the triple differential cross sections (TDCS) of multi-electron atom potassium (K) single-ionization by electron impact at the incident electron energy of 10.34, 14.34, 19.34, 24.34, 34.34, 44.34, 54.34 and 64.34 eV respectively in the coplanar symmetric geometry. Optimized effective potential (OEP) has been chosen in our calculation. We treat approximately the final-state as a Coulomb three-body interaction problem of scattered electron, elected electron and potassium ion. The ionization of potassium atom takes place in the valence shell 4S state. Incident electron and the two outgoing electrons are in the same plane, with equal scattering angle separated on both sides of the direction of incident electron. The ionization energy of potassium atom is 4.34eV and the two outgoing electrons share the excess energy equally. The DS3C and 3C calculation are compared with the recent experimental data of Murray and the DWBA (Distorted Wave Born Approximation) results. It is observed that 3C results at excess energy of 6,10 and 15 eV deviate from experimental data seriously. With the incident energy increases, 3C results are more and more in line with the experimental data. However, compared with 3C model the DS3C method which considered the dynamics screening between two-body Coulomb subsystems in the final state is able to reproduce most of the trend of experimental data and in good agreement with DWBA results. It shows that the DS3C method which is on the basis of the amendment on 3C model by introducing Sommerfeld parameters and the application of optimized effective potential to multi-electron atoms are successful.