Total charge-transfer cross sections for H+, H2+, H3+ He+, N+, N2+, Ne+, Ar+, Kr+, and Xe+ incident on Cs

The total cross section for electron capture has been measured for H+, He+, N+, Ne+, Ar+, Kr+, and Xe+ incident on a Cs vapor target. The energy range investigated was 40--120 keV for incident protons, 30--140 keV for incident N+, and 20--200 keV for the incident noble-gas ions. Also measured was the total attenuation cross section for H2+, H3+, and N2+ incident on Cs in the energy range 30--160 keV. These attenuation cross sections result from either electron capture or breakup of the incident molecular ion. At velocities below 5 x 105 m/sec, the various cross sections are different both in magnitude and velocity dependence. In the velocity range (0.5--1.5) x 106 m/sec, the cross sections for the various incident ions are almost completely independent of the identity of the incident ion. At velocities above 1.5 x 106 m/sec, the individual cross sections are different from one another again. The behavior of the measured cross sections is discussed in terms of a theoretical model for near-resonant charge transfer