Experimental evidence has been found for consecutive projectile-target-projectile (triple) and projectile-target-projectile-target (quadruple) “ping-pong” scattering of ionized target electrons in single ${\mathrm{C}}^{+}+\mathrm{Xe}$ collisions at 150 and $233\mathrm{keV}/u$ impact energies. Distinct signatures of the multiple electron scattering contributions to the high-energy part (300–3400 eV) of the double differential electron spectra have been separated and identified with the help of reference measurements using ${\mathrm{He}}^{+}$ projectile ions and different calculations.

• Received 27 February 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.073201