Status of Charge Exchange Cross Section Measurements for Highly Charged Ions on Atomic Hydrogen*

Total cross sections of charge exchange (CX) for C$^{5+}$, N$^{6+}$, and O$^{7+}$ ions on ground state atomic hydrogen are measured in an extended collision energy range of 1 - 20,000 eV/u. Absolute CX measurements are performed using an improved merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source mounted on a high voltage platform. In order to improve the problematic H$^{+}$ signal collection for these exoergic CX collisions at low relative energies, a new double focusing electrostatic analyzer was installed. Experimental CX data are in good agreement with all previous H-oven relative measurements at higher collision energies. We compare our results with the most recent molecular orbital close- coupling (MOCC) and atomic orbital close-coupling (AOCC) theoretical calculations.