Effects of dynamical screening on single ionization of sodium by electron impact in doubly symmetric geometry

Abstract

A dynamically screened three-Coulomb-wave model (DS3C) is applied to study the single ionization of sodium by electron impact. Triply differential cross sections (TDCS) are calculated in doubly symmetric geometry at excess energies of 6, 10, 15, 20, 30, 40, 50, and 60 eV. Comparisons are made among DS3C and the latest experimental data and such theoretical predictions as the three-Coulomb-wave function approach, the distorted-wave Born approximation, and the nonperturbative convergent close-coupling method. The angular distribution and relative magnitude of the present TDCS are found to qualitatively reproduce the reported experimental data. It is shown that dynamically screened effects are important in the geometries studied here.

Triple differential cross sections of magnesium in doubly symmetric geometry

“…The three-Coulomb-wave (3C) [17] and the dynamically screened 3C (DS3C) [18] are well known and have been shown to be capable of predicting the shapes of cross sections for various types of (e, 2e) and positron-impact ionization processes. [17][18][19] The description was extended to (e, 2e) cross sections of sodium [20,21] and potassium [22] and reproduced most of the features of the triple differential cross section in agreement with the experimental results.…”

“…Following the idea of Ref. [20], we study the triple differential cross section of magnesium in the coplanar symmetric geometry using a parameterized optimized effective potential for the alkaline core, both in the determination of the bound state wave function of the target and in the interaction potential of the incoming electron with the target. The effect of dynamical screening has been studied.…”

Effects of dynamical screening on single ionization of potassium by electron impact in doubly symmetric geometry

“…The dynamically screened three-Coulomb-wave (DS3C) is well known and has been shown to be capable of reproducing a part of the experiments for low incident energy [12][13][14]. The description was extended to (e, 2e) cross-sections of sodium [15] and showed quite good agreement with experiment in the whole energy range.…”

“…Following the idea of [15], we study the triple differential cross-section (TDCS) of potassium in the coplanar symmetric geometry using a parameterized optimized effective potential for the alkaline core both in the determination of the bound-state wave function of the target and in the interaction potential of the incoming electron with the target. The effect of dynamical screening has been studied.…”

“…The calculations have been done in doubly symmetric kinematics, which have been carried out numerically following the method described in our earlier work [15] with necessary modifications.…”