Speaker
Description
Emission spectroscopy measurements of N2/CH4 plasma are presented from 350 to 850 nm. The high-temperature plasma is generated at atmospheric pressure using a 50-kW Inductively Coupled Plasma (ICP) torch. The plasma is found to be close to LTE at ~ 6900 K and is then passed at high velocity through a water-cooled tube. The water-cooled tube induces rapid cooling and fast recombination. Spatially resolved emission measurements are presented at the torch exit (entrance to the water-cooled tube) and at the exit of the water-cooled tube. Several different tube lengths are currently being studied. The spectra are calibrated in absolute intensity and wavelength. The measured spectra are compared to simulations using the SPECAIR line-by-line radiative code, which has been updated using the trihybrid Exomol database. The collected data will be used to obtain the evolution of the rotational temperature and the density of the radiating states.
Summary
This work aims to study a recombing plasma of N2/CH4, representative of Titan's atmosphere. In this work, we performed experimental measurements of temperature evolution and species densities of the recombining plasma. These experimental
measurements will later be used to validate a chemical kinetic model.
