Spectrally Resolved nsTALIF Imaging of O Atoms Near a Reacting Copper Surface in the UIUC Plasmatron X Facility

In this work, we report progress on spectrally resolved nanosecond two-photon absorption laser-induced fluorescence (nsTALIF) measurements of O atoms to probe radial property distributions within the reacting boundary layer above a water-cooled copper sample in the 350 kW Plasmatron X Facility. Radial beam images from spectral nsTALIF scans were acquired at various locations, spanning from the boundary layer edge to the sample surface, with sufficient spatial resolution to capture critical sub-millimeter temperature and species density gradients near the material surface. Preliminary rotational temperature measurements have shown encouraging agreement with nitrogen (N2) rotational temperatures obtained through not yet reported efforts using coherent anti-Stokes Raman spectroscopy (CARS). Additionally, relative number density measurements along the stagnation line and across radial profiles exhibit promising trends. Efforts are ongoing to fully calibrate the system for determining absolute species concentrations.