Ionization and charge transfer in collisions of singly charged intermediate-energy heavy ions with gas targets.

Absolute total and partial cross sections for charge transfer and ionization are presented for collisions of C$^+$, F$^+$, Cl$^+$, and Cl$^{++}$ projectile ions with H$_2$, He, Ar, Ne, N$_2$, H$_2$O, and CH$_4$ gas targets in the energy range of 25 - 200 keV/u. The cross sections were determined by measuring post-collision projectile ion charge states in coincidence with target recoil ion charge states at the 2-MV tandem Van de Graaff accelerator facility at East Carolina University. Experimental data for collision processes for low-charge-state heavy ions incident on many-electron targets in this intermediate-energy range are particularly scarce. The present results are compared to available experimental data, to the recommended (theoretical) cross sections compiled by Janev, Phaneuf, and Hunter,\footnote{R.K. Janev, R.A. Phaneuf, and H.T. Hunter, Atom.~Data and Nucl.~Data Tables $\underline{40}$, 249 (1988).} and to scaling laws from Santos and DuBois.\footnote{A.C.F. Santos and R.D. DuBois, Phys. Rev. A. $\underline{69}$, 42709 (2004).} For electron capture for singly charged ions colliding with 10-electron targets (Ne and CH$_4$), the cross sections are observed to follow a single curve, independent of projectile Z, over several orders of magnitude of velocity.