ELECTRON IMPACT EXCITATION OF FINE-STRUCTURE LEVELS OF NEON-LIKE TITANIUM (Ti XIII)

Abstract

We present results of a Breit–PauliR-matrix calculation for the electron impact excitation of neon-like titanium, in which the 27 lowest fine-structure target levels arising out of the 4 lowest configurations 2s22p6, 2s22p53s, 2s22p53p, and 2s22p53dare included. These target levels are represented by configuration interaction wave functions using the 1s, 2s, 2p, 3s, 3p, and 3dbasic orbitals. The relativistic effects are included in the Breit–Pauli approximation via one-body mass correction, Darwin, and spin–orbit interaction terms in the scattering equations. For many transitions, complex resonance structures are found in the excitation cross sections. The excitation cross sections are integrated over a Maxwellian distribution of electron energies to give electron excitation rate coefficients over a wide temperature range from 150 to 600 eV. The relative populations for different electron densities and temperatures are also presented.