Rate coefficients for electron impact excitation, de-excitation and laser gain calculations of the excited ions Co(XVII) up to Br(XXV)

Abstract

Rate coefficients for electron impact excitation, de-excitation, and total depopulation of the excited ions Co(XVII) up to Br(XXV) of the sodium isoelectronic sequence are calculated according to the analytical formulas of Vriens and Smeets. A simple modification has been made by substituting effective quantum numbers in Vriens' formulas to be applicable for the ions under consideration. The energy levels and transition probabilities have been calculated using Hibbert's configuration interaction computer package (CIV3). Level population densities are then calculated by solving the coupled rate equations involving the 19 levels 1s22s22p6nl, where n = 3,4,5 and l = 0,1,2,3. Positive gain coefficients are displayed for the transitions 4p(2P1/2) → 4s(2S1/2) and 4p(2P3/2) → 4s(2S1/2) at three selected electron temperatures, namel, 1/4, 1/2, and 3/4 the ionization potential of each ion, respectively.