Evolution of fast heavy ion excitation in solid target - 0.83-2.4 MeV/u Brq+, Cuq+ + C -

To investigate the evolution of projectile inner shell excitation in solids, mean emission cross sections of projective Κ and L x-rays σ-barx (= x-ray yield/T) have been measured vs target thickness T. The collisions investigated are 52, 120, 150 MeV Cuq+ and 140 MeV Br q+ + C, where the projectile Κ-vacancy production takes place under the single collision condition, whereas projectile L-shell vacancies are dominated by the residual excitation collision. The authors focused on the σ-barx vs T relation in thin T region where projectile L-shell configurations will vary before equilibration is attained, which has not been clarified. Obtained relations for σ-barKX or σ-barLX vs T have been analyzed with the aid of observed x-ray energy shifts as well as the calculated cross sections of projectile inner shell ionization and excitation. In the present collisions, the dominant factors to provide the variation of σ-barx at T region of nonequilibrium L-shell configurations are considered to be in the variation of projectile inner shell excitation (Κ to L, or L to M) and the variation of fluorescence yield