Propensity for distinguishing two free electrons with equal energies in electron-impact ionization of helium
MetadataShow full item record
©2015 American Physical Society. We report a combined experimental and theoretical study on the electron-impact ionization of helium at E0=70.6eV and equal energy sharing of the two outgoing electrons (E1=E2=23eV), where a double-peak or dip structure in the binary region of the triple differential cross section is observed. The experimental cross sections are compared with results from convergent close-coupling (CCC), B-spline R-matrix-with-pseudostates (BSR), and time-dependent close-coupling (TDCC) calculations, as well as predictions from the dynamic screening three-Coulomb (DS3C) theory. Excellent agreement is obtained between experiment and the nonperturbative CCC, BSR, and TDCC theories, and good agreement is also found for the DS3C model. The data are further analyzed regarding contributions in particular coupling schemes for the spins of either the two outgoing electrons or one of the outgoing electrons and the 1s electron remaining in the residual ion. While both coupling schemes can be used to explain the observed double-peak structure in the cross section, the second one allows for the isolation of the exchange contribution between the incident projectile and the target. For different observation angles of the two outgoing electrons, we interpret the results as a propensity for distinguishing these two electrons - one being more likely the incident projectile and the other one being more likely ejected from the target.
Showing items related by title, author, creator and subject.
Comparison of experiment and theory for superelastic electron-collision studies from laser-aligned magnesiumPursehouse, J.; Bostock, C.; Nixon, K.; Harvey, M.; Fursa, Dmitry; Bray, Igor; Murray, A. (2018)A combined experimental and theoretical study of superelastic electron collisions from laser-aligned magnesium atoms for a range of collision energies from 35 to 55 eV is presented. Mg24 atoms were excited from the 3S01 ...
Bray, Igor; Fursa, Dmitry; Kadyrov, Alisher; Stelbovics, Andris; Colgan, J.; Pindzola, M. (2011)The convergent close-coupling and the time-dependent close-coupling methods are applied to the calculation of 64.6 eV electron-impact ionization of the ground state of helium resulting in two 20 eV outgoing electrons. The ...
Bray, Igor; Stelbovics, Andris (2013)The convergent close-coupling (CCC) method was developed in order to resolve the long-standing discrepancy between two consistent experiments and all available theories for 2p excitation of atomic hydrogen  . The method ...