Coincidence study of electron transfer to the continuum process in collisions at intermediate energies

Energy distributions of electrons ejected into the forward direction in 15-214 keV collisions were measured in coincidence with charge-state analysed outgoing projectiles. All spectra show a cusp-shaped peak centred at an electron velocity equal to that of the projectile. The peaks observed in coincidence with are associated with the electron-projectile Coulomb final-state interaction. On the other hand, the physical origin of the cusp-like structure observed in coincidence with neutral outgoing projectiles is still unknown. Here we present some new evidence that seems to indicate that this peak can be attributed to the dipole interaction between the emitted electron and an excited state of the outgoing projectile. The fractions of the cusp yields show that the electron transfer into the continuum process associated with emerging becomes more important for decreasing projectile energies.