Collision of Li\u3csup\u3e2+\u3c/sup\u3e with Li(2s) and Li(2p): Differential and Total Ionization; Discrete Excitations; Elastic Scattering, and Total Cross Section

The coupled pseudostate approximation (McGovern et al 2009 Phys. Rev. A 79 042707) has been applied to Li2+ + Li(2s, 2p0,±1) collisions at 16 MeV with emphasis on studying the fully differential ionization measurements of Ghanbari-Adivi et al in the azimuthal plane (2017 J. Phys. B: At. Mol. Opt. Phys. 50 215202). The states of the valence electron in the Li target are calculated using the model potential of Stein (1993 J. Phys. B: At. Mol. Opt. Phys. 26 2087). Altogether 164 states with angular momenta l = 0 to 9 are employed in the scattering calculation. It is assumed that the electron in the Li2+ is frozen in the 1s state and its screening of the Li2+nucleus is fully taken into account. Previous calculations on this system (3DW-EIS and CDW-EIS) have treated the Li2+as a bare ion with a nuclear charge of 2 au. Except for normalisation, agreement with the experimental data of Ghanbari-Adiviet et al is generally quite good. But, where agreement is best it is found that the cross section is very much first Born. Except in one case, quite good accord is also obtained with the 3DW-EIS calculations of Ghanbari-Adivi et al, particularly on normalisation. Screening by the 1s electron has little effect on the fully differential calculations undertaken here. The double differential cross section d2σ/dEdqt and the single differential cross section dσ/dE are also calculated. Here 1s screening is found to be important at large (transverse) momentum transfers qt and large ejection energies E. In addition, the pseudostate approximation gives cross sections for discrete transitions, total ionization and total scattering

Solid-Liquid Adsorption Based on External Mass Transfer, Macropore and Micropore Diffusion

A mass transfer model has been developed based on external film mass transfer, macropore diffusion and micropore diffusion to explain the adsorption of pollutants from aqueous solutions onto adsorbent particles. A computer program has been developed to facilitate analysis of the model in order that theoretical concentration decay curves may be compared with experimental data. A brief comparison has been made for the adsorption of Acid Blue 25 dye on chitin and phenol on carbon. However, the main purpose of the paper is to show the mathematical development of the model using the basic equations of the branched pore theory developed by Peel et al. (1981, A.I.Ch.E. J. 27, 26) and undertake a sensitivity analysis to study the effect of changing the four main parameters, namely, the external film mass transfer coefficient, the surface diffusion coefficient, the branched pore rate coefficient and the fraction of total adsorptive capacity in the macropores. © 1987

PCI, polarisation and exchange effects in (e,2e) collisions

The role of post-collisional, polarisation and exchange effects in energy sharing (e,2e) collisions is considered. Methods of including such effects are assessed. Results are presented for the ionisation of hydrogen and helium gases in coplanar geometry. Results are also presented for the ionisation of helium, argon and xenon in perpendicular plane geometry

(e,2e) measurements on lithium with spin-polarized beams of electrons and atoms

Streun M, Baum G. (e,2e) measurements on lithium with spin-polarized beams of electrons and atoms. In: Whelan CT, Dreizler RM, Macek JH, Walters HRJ, eds. New Directions in Atomic Physics. Physics of Atoms and Molecules Series. New York: Kluwer Academic / Plenum Press; 1999: 263-268

Analysis of semi-relativistic approximations for relativistic (e,2e) experiments

We analyse the validity of using semi-relativistic approximations in the Coulomb Born approach, for both bound and continuum wave-functions, when describing theoretically relativistic (e, 2e) experiments. A comparison with absolute experimental data is made for the ionization of the K-shell of gold and silver, in coplanar symmetric and asymmetric geometries

Triply differential single ionization cross sections in coplanar and non-coplanar geometry for fast heavy ion-atom collisions

We have performed a kinematically complete experiment and calculations on single ionization in 100 MeV/amu C6+ + He collisions. For electrons ejected into the scattering plane (defined by the initial and final projectile momentum vectors) our first- and higher-order calculations are in good agreement with the data. In the plane perpendicular to the scattering plane and containing the initial projectile axis a strong forward-backward asymmetry is observed. In this plane both the first-order and the higher-order calculations do not provide good agreement neither with the data nor amongst each other