Electron Impact Excitation of Kr XXVIII

Collision strengths (Ω) are calculated for all 6328 transitions among the lowest 113 levels belonging to the 2s22p5, 2s2p6, 2s22p43l, 2s2p53l, and 2p63l configurations of fluorine-like Kr XXVIII, using the Dirac Atomic R-matrix Code (DARC). All partial waves with angular momentum J≤40 are included, sufficient for the convergence of Ω for forbidden transitions. For allowed transitions a top-up is employed to obtain converged values of Ω up to an energy of 400 Ryd. Resonances in the thresholds region are resolved in a narrow energy mesh, and results for effective collision strengths (ϒ) are obtained after averaging the values of Ω over a Maxwellian distribution of electron velocities. Values of ϒ are reported over a wide temperature range below 107.1K, and the accuracy of the results is assessed. In addition, effective collision strengths are listed for the temperature range 7.0 ≤ log Te (K) ≤ 9.0, obtained from non-resonant collision strengths generated with the FAC code.