Comparison of experimental and theoretical fully differential cross sections for single ionization of the $2s$ and $2p$ states of Li by Li²⁺ions

Abstract

This paper presents experimental measurements of the fully differential cross section for 16 MeV Li2+ single ionization of ground and the excited state of Li in the azimuthal plane. Data were obtained for three different ejected electron energies and two different projectile momentum transfers. The experimental results are compared with theoretical three-body continuum distorted wave-Eikonal initial state calculations and reasonable good agreement is found between theory and experiment. Theory predicts a double peak structure for one of the measured cases and the physical effects producing the double peak are investigated by performing calculations with different interactions either turned on or off.

Fully differential cross sections for Li2+-impact ionization of Li(2s) and Li(2p)

“…For these cases, the 3DW-EIS [24] and CDW-EIS theories predict totally different behaviors for the ejected electron spectra. Such an obvious difference has been also reported between 3DW-EIS and FBA [24]. For (E e = 2 eV, q = 1 a.u.…”

“…FDCSs for ionization of Li(2s) targets calculated using the prior version of CDW-EIS including the NN interaction are compared with their corresponding results obtained using the 3DW-EIS model [24] and with their experimental values [24] in figure 2. The results of both theories are normalized to the experiments at the binary peak.…”

“…A similar comparison is made for single ionization of the 2p excited states of Li targets in figure 3. Since the targets were experimentally prepared [24] with relative populations of 86%, 9%, and 5% for the magnetic substates with m = −1, m = 0, and m = −1, respectively, the cross sections are calculated using these experimental weights. If the sublevels with m = ±1 were equally populated, a symmetric angular distribution is expected for both the calculated and the measured cross sections around φ e = 180 • .…”

“…Third, in 3DW-EIS amplitude there exists an extra term coming from a proper rearrangement of the terms included in the exact amplitude, and taking into account the additional higher-order effects through the final-state perturbation, while this term is absent in CDW-EIS. [24].…”

Doubly differential cross sections for ionization of lithium atom by protons and O8+ ions

“…The comparison between advanced perturbative theories, three-body continuumdistorted-wave (3DW) and three-body continuum-distortedwave eikonal-initial-state (3DW-EIS), was reported in Ref. [13]. Large discrepancies between the results of the CDW-EIS and 3DW-EIS approaches at large momentum transfers were recently found in Ref.…”