Emission spectroscopy at high frame rates during ablation tests of meteorite samples in plasma wind tunnel
R. Ravichandran, S. Loehle, F. Hufgard, D. Leiser, F. Zander, L. Ferrière, J. Vaubaillon, P. Matlovič, J. Tóth
Available online 28 September 2023, 115818
“Optical emission spectra between 522-580 nm of ablating meteorites have been recorded at frame rates as high as 1 kHz for the first time during ground testing with simultaneous spatial and temporal resolution. A novel high frame rate emission spectroscopy arrangement has been developed and employed to diagnose the ablating meteorites in several experimental campaigns. In addition to the identification of species from emission lines detected, the resulting high-speed spectral data were used to study the temporal and spatial evolution of melting droplets and the associated spectral signatures. The time history of radiance from the atomic species emission was used to interpret the fragmentation behavior of various meteorites. Chelyabinsk meteorite exhibit almost constant radiance over time indicating steady droplet detachment whereas Ragland meteorite shows infrequent radiance peaks corresponding to random fragmentation/droplet detachment of varying sizes. A gradual rise in radiance history from iron meteorite Mount Joy shows that it takes finite time for melting and accumulation of droplets.