The<i>K</i>-Shell Population of Ions Penetrating Ferromagnetic Solids

Abstract

K-vacancy fractions as well as cross sections for creation and quenching of K-vacancies have been measured for O, F, Mg, Si, and S projectiles moving through solid Fe, Co, Ni and Gd at velocities ranging from 1.5v0 to 10.5v0. Two different techniques were used, i.e., the beam-X-ray and the probe-layer method, respectively. Based on comparisons with semiempirical estimates a number of different K-shell processes were identified. Direct Coulomb ionization and excitation and electron capture dominate at high velocities, whereas collision-perturbed deexcitation and quasi-molecular effects are important at low velocities. Distinct level-swapping effects are observed for O and F in Fe. The present data provide the basis for an investigation of the origin of the transient magnetic field in a recent paper.