L-shell X-ray production cross sections in Nd, Gd, Ho, Yb, Au and Pb for 25-MeV carbon and 32-MeV oxygen ions☆

Abstract L-shell X-ray production cross sections in 60 Nd, 64 Gd, 67 Ho, 70 Yb, 79 Au and 82 Pb have been measured for incident 25 MeV 6 12 C + q ( q = 4, 5, 6) and 32 MeV 8 16 O + q ( q = 5, 7, 8) ions. Measurements were made on targets ranging in thickness from 1 to 100 μg/cm 2 . Enhancement in the L-shell X-ray production cross section for projectiles with one or two K-shell vacancies over those for projectiles with no K-shell vacancies is observed. The sum of direct ionization to the continuum (DI) plus electron capture (EC) to the L, M, N… shells and EC to the K-shell of the projectile have been extracted from the data. Calculations in the first Born approximation are ~10 times larger than the data. Predictions of the ECPSSR theory that accounts for the energy-loss, Coulomb deflection, perturbed-stationary state and relativistic effects are in good agreement with the data for both ions.