Stark-broadened hydrogen line profiles predicted by the model microfield method for calculating electron number densities

This report is the first account on the application of theoretical Stark-broadening profiles predicted by the model microfield method (MMM) to estimate electron number density (ne) in several laboratory plasmas. The determination of ne is accomplished by least-squares fitting of the entire emission profile or the wing portions of the emission profile of the Hβ line (486.13 nm) to the theoretical Stark-broadened profiles. Experimental profiles obtained for the Hβ line from argon and helium inductively coupled plasmas (ICP), a glow discharge, and a high-voltage spark are used to test the new MMM profiles. Results are contrasted with data predicted by the traditional ‘Unified Theory’. Compared to the ‘Unified Theory’, the MMM profiles are more accurate in the line center and span over a wide range of temperature (2500–80 000 K) and electron number densities (1×1010–1×1017 cm−3).