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Meteor wake spectra: laboratory modeling of atomic and molecular emission in laser-induced plasmaтезисы доклада
- Авторы: Zakuskin Aleksandr S., Beglaryan Babken G., Berezhnoy Alexey A., Labutin Timur A., Stolyarov Andrey V.
- Сборник: Book of abstracts of European Conference on Laboratory Astrophysics ECLA 2020
- Тезисы
- Год издания: 2021
- Место издания: Анакапри, Италия
- Аннотация: Laser-induced plasma is widely used as an emission source for laboratorysimulations of dierent objects. The properties of laser plasma vary signi-cantly depending on the pressure and composition of the environment, as wellas during the evolution of the plasma plume. This unique property combinedwith the typical range of electron temperature (from 0.2 to 4 eV ) and electronnumber density (1015 1019cm3) make it a promising emission source forstudy of radiation from various objects in atmosphere (meteor wake, airglow)and in outer space. We aimed to register spectra of FeO and CaO bands inlaser plasma as close as possible to the ones observed during the Benesov bolideevent. This kind of laboratory modeling of molecular emission cannot be calcu-lated theoretically and can help to investigate and characterize the particularconditions of the Benesov meteor wake.We obtained emission spectra of laser plasma under dierent pressures (from0.16 Torr to atmospheric) and observation times while ablating samples ofFe3O4, CaCO3. In each case plasma conditions were characterized by deter-mining electron temperature via construction of Boltzmann plot with 20 to30 atomic lines. Electron number density was estimated by Stark broadeningwhere possible. Study of spatial distribution of emitting atoms and moleculesin plasma with precise plasma diagnostics allows to make conclusions about ex-istence or absence of the local thermodynamic equilibrium. We found that theratios of molecular and atomic components dier greatly in spectra of Benesovand laboratory ones at the same pressure. Varying the pressure of labora-tory experiment proves that Benesov wake was formed under 7-10 times higherpressure than the ambient one on the corresponding altitude.Also, the obtained data show that the formation of FeO in plasma occurswith involvement of oxygen from the ablated material, but not from the sur-rounding atmosphere. On the contrary, CaO is formed primarily using oxygenfrom atmosphere. Therefore, abundance and of FeO and intensity of its emis-sion in space objects may not depend on the pressure of the surrounding media,while CaO should have a strong dependency.This work was supported by the Russian Science Foundation (grant 18-13-00269-).
- Добавил в систему: Закускин Александр Сергеевич