Observation of Oscillatory (Interference?) Structure in the Forward Peak from Fast-Projectile Electron Loss

Significant unexplained oscillator structure has been observed in the wings of the forward electron-loss peak from 1.6-3.9-MeV/amu ${\mathrm{O}}^{q+}$ and ${\mathrm{Si}}^{q+}$ ions traversing Ne and Ar gases. On the basis of the observed projectile $Z_1$, $q$, and velocity and target $Z_2$ dependencies, this structure appears likely to arise from interference of amplitudes describing alternative channels for populating projectile-centered continuum states, conceivably including channels involving simultaneous ejection of two or more electrons.