Constancy of Calculation Procedure for Radiation Lifetimes

Abstract

Purpose: Radiation lifetimes of atom and ion energy levels refer to fundamental physical constants which knowledge of is necessary in many fields of both, fundamental or applied science. The knowledge of these values is necessary at search of active medias for optical generators, for plasma both laboratory or astrophysical and other diagnostics. While lifetime calculation, it’s very vital to evaluate the impact of simplifications and supposition, put on the basis of calculation procedure. In particular, to evaluate impact of configuration superposition which consideration significantly complicates calculation model. The present work investigates this issue on a particular example of spectrum of sixfold wolfram ion W VII. Methods: Superposition of configurations 4f 13 5p6 6p + 4f 14 5p5 6p in the spectrum of erbium-similar W VII is investigated by semiempirical method of intermediate coupling with the use of energy experimental levels known from the literature. Together, wave functions of intermediate binding of odd configurations have been found in a single-configuration approximation; radial integrals, that’re necessary for transfer to absolute scale of transition probabilities, are calculated in the form of length with Hartree-Fock functions. Lifetimes of 4f 135p66p levels are calculated by summarizing electric dipole transition probabilities 4f 13 5p6 6p+ 4f 14 5p5 6p → 4f 13 5p65d, 4f 13 5p66s. Results: It’s been obtained that configuration essential mixing takes place for states with total angular momentum J = 3. Values of level lifetimes have been appeared to be insensitive to influence of configuration mixing. As to author’s opinion, it’s connected with that the lifetimes are defined by the probabilities of the most intensive transitions which in its turn, are the least sensitive to possible inaccuracies in calculation procedure. Practical significance: Values of lifetimes of levels 4f 13 5p6 6p in W VII spectrum, that are absent in contemporary databases at the moment, are practically significant.