Double-differential cross sections (DDCS’s) for the production of binary-encounter electrons (BEE’s) are reported for 30-MeV ${\mathrm{O}}^{\mathit{q}+}$+${\mathrm{O}}_2$ collisions. The BEE DDCS’s were measured at θ=0° with respect to the beam direction for projectile charge states q=4–8. The measured BEE DDCS’s were found to increase with decreasing charge state in agreement with other recent BEE results employing simpler ${\mathrm{H}}_2$ and He targets. Impulse-approximation calculations of BEE production for θ=0°–45° are also presented, in which it is assumed that target electrons undergo elastic scattering in the screened Coulomb field of the projectile ion. These calculations are shown to be in agreement with our data at θ=0° where only 2s and 2p target electrons are considered.

• Received 25 October 1993

DOI:https://doi.org/10.1103/PhysRevA.49.R3155