Excitation of ions of the lithium isoelectronic sequence in the relativistic Coulomb-Born approximation

Cross sections for the electron-impact excitation of the 2p1/2 and 2p3/2 states of the lithiumlike ions C³⁺, Fe²³⁺, Mo³⁹⁺, and W⁷¹⁺ are calculated in the relativistic Coulomb-Born approximation. A range of incident electron energies from the 2p1/2 threshold to (approximately) ten times the 2p3/2 threshold is considered. The most significant relativistic effects result from the spin-orbit splitting of the $2p$ states. An interpolation formula is presented which permits the estimation of these cross sections for similar ions of intermediate charges.