Interference between electric and magnetic amplitudes for K shell excitation of high-Z H-like projectiles

We report an investigation of projectile K shell excitation for high-Z ions in relativistic ion-atom collisions. For the case of H-like Bi, the excitation process is unambiguously identified by observing the radiative decay of the excited levels to the vacant 1s shell, in coincidence with ions that did not undergo any charge exchange in the reaction target. The results are compared with detailed relativistic calculations, showing that the magnetic interaction is of considerable importance for the K shell excitation process in high-Z ions. For excitation to the L shell sublevels, the experimental data confirm that the magnetic part of the Lienard-Wiechert interaction must be added coherently with the electric part leading to a significant reduction of the K shell excitation cross section. (orig.)