Exit charge-state dependence of convoy-electron production in heavy-ion–solid collisions

We have measured the yield of convoy electrons in coincidence with the emergent ionic charge state $q_e$ for heavy ions in equilibrium-thickness C foils. The data extend the range of previous measurements to include higher-Z projectiles and lower energies. The dependences found range from an approximately $q_e$-independent yield for ${\mathrm{O}}^{\mathrm{q}+}$ projectiles to a dependence which peaks near $q_e$=9 for ${\mathrm{Si}}^{\mathrm{q}+}$ and $q_e$=11 for ${\mathrm{Cl}}^{\mathrm{q}+}$ projectiles, respectively. We have been able to interpret the observed $q_e$ dependences in terms of primary-electron-loss events in the foil.