1s 2s2p Research Articles

Incident electron energy dependence of ejected-electron intensities corresponding to excitation of autoionising states in Li I

Excitation functions for lithium were obtained by measuring the intensity of ejected electrons at 75 degrees to an incident electron beam. The maximum incident electron energy was 550 eV. Excitation functions were obtained for the 1s(2s2p 3P)2P, (1s2s2)2S, (1s2s2p)4P and 1s(2s2p 1P)2P states. The excitation function for 1s(2s2p 1P)2P suggests that an optically forbidden level lies close to the optical level and an electron configuration is suggested for this additional level. The very recent experimental data for caesium presented by Pejcev et al. (1977) are reconsidered in the light of the present work.

Studying Li and He? in the 1s2s2p configuration

Expressions are derived for the nonrelativistic energy of the 1s2s2p configuration. In both the possible electron momentum binding systems (1s2s)2p and 1s(2s2p) values are determined for the parameters of the generalized hydrogenlike analytical radial orbitals for a lithium atom and a negative helium ion. The Li and He− energy spectra in the 1s2s2p configuration are compared with the theoretical calculations of other authors and with experimental data.

Atomic and molecular calculations with the model potential method. IV

Results of model potential calculations are reported for the ground state of transition metal elements, Sc through Zn. We also present satisfactory results of calculations on both the ground and selected excited states of Fe, Fe++, Ni, and Ni++ with the model potential method. The model potentials were constructed to replace the 1s2 2s2 2p6 3s2 3p6 core, and also the 1s2 2s2 2p6 3s2 core, thus including 3p electrons as the ’’valence’’ electrons.

Auger electron emission spectra from foil and gas excited carbon beams

Auger electron emission spectra from 2 MeV C + ion excited by collisions with thin carbon foils and Ne gas are presented. The similarity of qualitative features for the C + → C (foil) and C + → Ne spectra indicates the similarity of ionization mechanisms for beam foil and beam gas excitation. The spectra were normalized to the lowest lying Li-like quartet state (1s 2s 2p) 4P 0 in carbon by comparison with time delayed foil excited electron decay-in-flight spectra. Comparison to Hartree-Fock calculated transition energies indicates that transitions in three and four electron carbon ions dominate the prompt spectra.

Effects of the configuration interaction on the K-Shell auger spectrum of neon

New calculations based on the nonrelativistic Hartree-Fock-Slater model, incorporating interaction between the final states (1s 22s 0sp 6 1S 0) and (1s 22s 22p 4 1), are presented for neon. These theoretical results remove an outstanding disagreement between earlier theoretical calculations and the high-resolution measurements.

Close Coupled Calculations of Electron-Hydrogen Atom Scattering Using a Noniterative Integral Equation Technique

A noniterative integral equation approach to electron-hydrogen atom scattering, including exchange, has been developed for the case in which all available channels are open. The technique has been implemented on a computer for the calculation of cross sections in the 1s–2s strong coupling exchange approximation and the 1s–2s–2p close coupling exchange approximation. The results of these calculations were found to be in good agreement with those obtained by the iterative solution of the differential equations. The merits of the noniterative integral equation technique are compared with other computational schemes for obtaining scattering information.

Lifetime measurements of autoionizing levels by the beam-foil technique

We have measured natural linewidths in doubly excited He I and Li I. They yield lifetimes of (7.5 ± 1.0) × 10 −14sec for 1s (2s2p 1P) 2P in Li I and (1.4 ± 0.2) × 10 −13sec for 2s 2 1S in He I.