Photoionization of the alkali molecular ions in geo-cosmical plasmas

Abstract

Opacities of the solar and stellar atmospheres are caused by a large number of radiative processes. Within development of more sophisticated stellar atmosphere models, we can further investigate known processes and include all processes not considered before. We calculate the average cross-section and rate coefficients for the photodissociation of the alkali molecular ions Li + 2 , Na + 2 and LiNa + ready for further use with a particular accent to the applications for astro plasma research and low temperature laboratory plasma research.

Photodestruction of Diatomic Molecular Ions: Laboratory and Astrophysical Application

“…In Figure 2 a,b and Figure 3 a,b we present a surface plot of the averaged cross-section for photodissociation of the , , and molecular ions as a function of for a wide range of temperatures T , which are relevant for modeling laboratory [ 13 ] and astrophysical plasmas (e.g., geo-cosmic plasmas) [ 10 , 11 , 28 ]. These figures and the shape of surfaces show that exist a noticeable difference between temperature dependence of the mean thermal photoionization cross-section for different species.…”

“…From [ 8 , 9 , 10 ] and from investigation in existing literature about the solar photospheric spectra, the absorption spectra of planetary atmospheres and the chemical composition of dust, it follows that alkali metals take part in the composition of cosmic objects [ 11 , 12 ]. It has been discovered and concluded that important characteristics of the brown dwarfs and extrasolar planets spectra might be attributed to resonance lines of alkali metal atoms broadened by collisions with ambient helium atoms and hydrogen molecules (see e.g., [ 13 , 14 ]).…”

“…Also, the average cross-section and the corresponding spectral absorption rate coefficients for the photodissociation of the mentioned molecular ions are obtained for a wide region of wavelengths and temperatures. The presented results here are ready for further use with a particular emphasis on the applications for astro-plasma research and low-temperature laboratory plasma research [ 10 , 13 , 25 , 26 , 27 ].…”

A Decade with VAMDC: Results and Ambitions

“…MolD contains photodissociation cross sections for individual rovibrational states of diatomic molecular ions as well as corresponding data on molecular species and molecular state characterisations calculated using a quantum mechanical method described in [110]. Since the previous VAMDC review [3], large amounts of new data concerning alkali molecular ions have been included for reference [111].…”

Chemi-recombination processes in astrophysical and low-temperature laboratory plasmas: the case of potassium

“…As referred over the recent years the collisional processes are of great interest to the scientists (Iacob et al, 2019;Ignjatović et al, 2019;Mihajlov et al, 2012). The reason for this is that they have an effect on the spectral properties of astrophysical and laboratory plasmas (see papers Tielens, 2013;Beuc et al, 2018a,b;Srećković et al, 2014;Ignjatović et al, 2020). Collisional processes involving various species including alkali atoms, ions, and small molecule ions can have an impact on the ionization level, atom excited-state populations, and optical properties (Mihajlov et al, 2011;Srećković et al, 2017).…”