Determination of arc plasma parameters of the AEDC HEAT H1 arc heater using optical emission spectroscopy

Abstract

Time-resolved spectral radiance emission measurements of the arc in the AEDC HEAT H1 Facility were successfully performed during the months of April and May of 1991. The HI Arc Heater is a segmented, vortex-stabilized arc heater used for materials testing under high enthalpy and pressure regimes. Emission spectra of the arc were acquired through a joint effort of Sverdrup Technology, Inc. and Calspan Corporation during a series of 15 HEAT HI technology tests in supprt and under the direction of Dr. Orlando Hankins. Data was acquired for steady-state arc currents of 700 to 1200 A at neutral pressures of 40 to 120 atmospheres. Analysis of the spectra has revealed 2 nmher of ztonic mission lines of drgon, nitrogen, and oxygen on top of a continuum emission. The temporal increase of the plasma density, obtained from Stark broadening measurements, and the evolution of the electron temperature determined by comparing measured line intensity ratios to collisional-radiative model calculations will be described.