Measurement of Excitation Equilibrium Departure Evolution in an Argon Pulsed Plasma

This work reports information about the temporal evolution of the excitation equilibrium departure in a high current pulsed arc. An argon plasma has been created in a linear lamp by discharging a capacitor bank on its electrodes. Spatially and temporally-resolved measurements have allowed us to determine electron density N e and excitation temperature T with great accuracy. Single-wavelength interferometry and H α -Stark broadening have been used to measure N e (0.2–0.98× 10 23 m -3 ). Excitation temperature has been obtained from Boltzmann-plot of ArII lines and ranges in this experiment from 13500 to 26500 K. By assuming this temperature is equal to kinetic electron temperature and by comparing the theoretically predicted and the experimental ArII/ArI intensities ratios at each instant of the plasma life, it is possible to measure the departure of the excitation processe from local them dynamic equilibrium (LTE) conditions and to show the ionizing characteristics of this close-to-LTE plasma. Different t...