Calculations for electron-impact excitation and ionization of beryllium

Abstract

The B -spline R-matrix and the convergent close-coupling methods are used to study electron collisions with neutral beryllium over an energy range from threshold to 100 eV. Coupling to the target continuum significantly affects the results for transitions from the ground state, but to a lesser extent the strong transitions between excited states. Cross sections are presented for selected transitions between low-lying physical bound states of beryllium, as well as for elastic scattering, momentum transfer, and ionization. The present cross sections for transitions from the ground state from the two methods are in excellent agreement with each other, and also with other available results based on nonperturbative convergent pseudostate and time-dependent close-coupling models. The elastic cross section at low energies is dominated by a prominent shape resonance. The ionization from the (2s2p) 3 P and (2s2p) 1 P states strongly depends on the respective term. The current predictions represent an extensive set of electron scattering data for neutral beryllium, which should be sufficient for most modeling applications.

Electron impact excitation of N3+using theB-splineR-matrix method: importance of the target structure description and the size of the close-coupling expansion

“…The above expansion is similar to the one used in our recent calculations for electron scattering from neutral Be [20]. Usually we employ separate multi-configuration Hartree-Fock (MCHF) expansions for a more accurate representation of the low-lying states with equivalent electrons, in particular 2s 2 and 2p 2 in the present case.…”

A Relativistic Complex Optical Potential Calculation for Electron–Beryllium Scattering: Recommended Cross Sections

“…As a consequence of the above, there has been significant theoretical activity in attempting to calculate cross sections for electron scattering from Be. Focussing on the TICS here, we note plane wave Born approximation (PWBA) results that can be obtained from the method in the work of Deutcsh et al, 3,4 a distorted-wave with electron scattering (DWIS(N-1)) computation from the work of Bartlett and Stelbovics, 5 a Deutsch-Märk (DM) calculation from the work of Maihom et al, 2 the close coupling (CC) and R-matrix with pseudo-states (RMPS) results from the work of Zakrzewski and Ortiz, 6 a later convergent close coupling (CCC) and a new B-spline R-matrix (BSR) calculation from the work of Zatsarinny et al, 7 and our own optical potential (OP) computation (Blanco et al). 8 Note that as Be is not a particularly easy material to work with, there are no experimental cross sections currently available in the literature for it.…”

The Method of Interacting Configurations in Complex Number Representations: From Helium to the Complex Atoms

“…One of the goals of these investigations is to demonstrate that the ICCNR method can be useful for the complex atoms study on the level of popular R-matrix approach, see, e. g., [36]. The ICCNR method is applied here to the calculation of spectroscopic characteristics of AIS of Be, Mg and Ca atoms in the problem of the electron-impact ionization of these atoms.…”

“…[102], where the calculation procedure has been presented in details. Today the R-matrix method is the most spread in the complex atoms AIS investigations [36,102,103]. This method is widely applied for the scattering of photons and electrons on the complex atoms both in ordinary [102] and B-spline [103] formalism.…”