Equilibration Lengths for K‐Sfell Charge‐Exchange Processes for Fast Ions Traversing Foils — Evidence from Multiple‐Scattering Distributions and Auger‐Yield Measurements

Measurements on the angular distributions of fast ions traversing foils show a pronounced dependence of the multiple‐scattering widths upon the charge state of the emerging ions. These results can be explained in terms of the large scattering angles achieved by those ions that bear K‐vacancies. A quantitative model is described which demonstrates how the “memory” of K‐vacancy producing collisions gives rise to large multiple‐scattering widths in spite of apparent charge‐state equilibration. These data, together with related measurements on projectile Auger‐electron yields, permit determination of the equilibration lengths for K‐vacancy bearing fractions of ion beams traversing foils.