Ionization dynamics in fast ion-atom collisions. I. Energy and angular distributions of low-energy electrons emitted in ionization of He by bare carbon ions

We have studied the two-center effect (TCE) in ion-atom ionization by measuring the energy and angular distributions of the double-differential cross sections (DDCSs) (d(2)sigma/d epsilon d Omega) of the low-energy electrons emitted in a collision of He atoms with 2.5 MeV/nucleon C6+ ions. The electrons with energies between 0.1 and 300 eV were detected for 13 different emission angles between 15 degrees and 160 degrees. From the measured DDCSs we have deduced the single differential cross sections such as d sigma/d Omega and d sigma/d epsilon and the total cross section. The data have been compared with the continuum distorted wave eikonal initial state calculations with H-like and Hartree-Fock-Slater wave functions for the initial and final state of the electron and first Born calculations. The forward-backward asymmetry parameter also has been deduced io study the TCE in detail. In the following paper [Lokesh C. Tribedi et at, Phys. Rev. A 58, 3626(1998)] we have explored the collision dynamics by deducing the momentum distributions of the electron, the recoil ion, and the projectile. [S1050-2947(98)04810-0].