Relative intensities of Delta n=0 transitions within the n=2 and n=3 levels in nitrogenlike Ar XII from a theta -pinch plasma.

Abstract

In a well diagnosed transient {theta}-pinch deuterium plasma with a small concentration of argon added, the relative intensities of the {Delta}{ital n}=0 transitions within the {ital n}=2 and {ital n}=3 levels were measured at the maximum abundance of the Ar XI ion. The emission spectra of the intrashell transitions were observed in the wavelength range 149--225 A and 434--784 A, respectively. Theoretical predictions for electron collision strengths, oscillator strengths, and radiative decay rates were used from the literature to determine the relative intensities which were compared to the experimental results. Therefore, electron collisional excitation rate coefficients and radiative decay probabilities could be indirectly verified. General overall agreement is obtained with a collisional-radiative model which includes 72 levels, although some transitions deviate.