Extension of the theory for the intensities of dipole forbidden spectral lines in a plasma.

A consistent theory describing the effect of appearance of dipole-forbidden spectral line (FSL) in a plasma is developed. The theory accounts only for the contributions of quasi-static ions to the FSL intensity, the boundary between these ions and the remaining ions being determined from a multiparticle description of the plasma microfield. The contribution of electrons has been treated in a standard manner. The present analysis has been performed for more complicated four-level schemes of the energetic spectrum of emitters than previous calculations by the authors. This result makes it possible to enlarge significantly the class of possible emitters and, therefore, of plasma accessible to the corresponding diagnostic technique.