The $L$-shell ionization processes of a Ne gas target associated with single-electron capture by bombardment of ${\mathrm{C}}^{q+}$ and ${\mathrm{O}}^{q+}$ $(q=2,3)$ are investigated using the projectile-recoil-ion coincidence method in the energy range from $80\text{to}400\mathrm{keV}∕\mathrm{u}$ $(v_p=1.8–4\mathrm{a.u.})$. The cross-section ratios $\left(R_{k1}\right)$ of $k$-fold ionization to single capture are compared with the results for ${\mathrm{He}}^{2+}\text{−}\mathrm{Ne}$ collisions by Dubois [Phys. Rev. A 36, 2585 (1987)]. All the velocity dependences are quite similar. The ratios increase as the projectile energy increases in the lower-energy region, reach the maxima for projectile energies around $E_{\max }=160q^{1∕2}\mathrm{keV}∕\mathrm{u}$, and then decrease at higher energies. These results qualitatively agree with our calculations in terms of the Bohr-Lindhard model within the independent-electron approximation.

• Received 28 September 2008

DOI:https://doi.org/10.1103/PhysRevA.78.062718