Distorted-wave methods in ion-atom excitation

Total and differential cross sections for excitation are calculated using three distorted-wave methods: the continuum distorted-wave (CDW) method, the Coulomb peaking impulse approximation (CPIA) and the symmetric eikonal (SE) method. All three methods have the correct Coulomb asymptotic behaviour on both channels. Results for proton-hydrogen excitation to levels n=2, 3 and 4 are presented. Differential cross sections are also calculated and compared with experimental results. The CDW method is found to present a doubtful enhancement that vanishes at high projectile velocities. The dependence of the excitation process on the projectile Coulomb charge is also studied. Cross sections for single excitation of Fe 24+ by impact of bare and neutral projectiles are calculated and compared with recent experiments.