Laser Diagnostics of Inductively Heated Oxygen, Nitrogen and Air Flows

Abstract

Laser absorption spectroscopy was applied for diagnostics of inductively heated plasma generator IPG3 air and nitrogen flows. Although no absorption signal could be detected in the nitrogen flow, temporal variation of absorption profiles at OI 777.19 nm were measured in the air flow. As a result, the flow properties were found to fluctuate at 300 Hz with the plasma emitted duration of 46%. The specific total enthalpy and degree of dissociation in oxygen and nitrogen were estimated from the deduced total temperature assuming thermo- chemical equilibrium in the discharge tube. Consequently, the averaged total enthalpy, degree of dissociation in oxygen and nitrogen in the emitted duration time were estimated as 23.5±10.1 MJ/kg, 98% and 44 %, respectively.