Temperature diagnostics of plasma under optically-thin conditions

Abstract

For temperature diagnostics of plasma, using the silicon spectral lines emitted from the solar transition region, under the optically-thin conditions, we discuss temperature diagnostics of the quiet sun in some typical features. For the silicon IV 112.8325 nm and 140.2770 nm spectral lines, using the observed intensity ratio, we calculate the temperature of faint cell center, average cell center, average quiet sun, average network, bright network and very bright network of the quiet sun, and results are in good agreement with those predicted at the [Formula: see text] ionization equilibrium temperature of formation of the silicon IV, and we discuss the temperature when the observed intensity varies from 0.05 to 0.2. This investigation will be significant for temperature diagnostics of plasma under the optically-thin conditions.