Researchers identify useful emission lines in the sun’s outer atmosphere

When finding out the solar spectrum, researchers typically seek for particular emission strains: outstanding wavelengths emitted by ions as their electrons transition from greater to decrease power ranges. Emission spectra of two iron ions, Fe IX and Fe X, are significantly helpful for finding out the sun’s outer ambiance. Nevertheless, each of those spectra comprise emission strains that may’t but be matched with identified electron transitions, limiting the data which might be gathered from them.

In a examine published in The European Bodily Journal D, researchers led by Alexander Fairchild at Columbia College, U.S., carried out new measurements of those spectra within the extreme-ultraviolet (EUV) area, which enabled them to unambiguously establish the particular ion related to these beforehand unmatched emission strains. Their outcomes may improve our understanding of a number of key properties of the sun’s outer ambiance.

Fairchild’s staff carried out their measurements at Lawrence Livermore Nationwide Laboratory in California, utilizing the Electron Beam Ion Entice (EBIT-I). This facility creates and traps extremely charged ions like Fe IX and Fe X utilizing an intense electron beam, then data their ensuing emission spectra.

The vary of wavelengths studied by the staff was particularly helpful because it allowed them to measure the ratio between two emission strains of Fe IX, predicted to be among the best density indicators within the sun’s outer ambiance. It additionally contains an essential Fe X emission line, induced by the interplay between the sun’s atmosphere and its intense magnetic area.

To confirm their outcomes, the researchers in contrast them with Fe IX and Fe X emission strains modeled by CHIANTI, the database most generally utilized by solar physicists to investigate and interpret the sun’s emission spectra.

For some emission strains, Fairchild’s staff discovered shut settlement between CHIANTI’s predictions and their experimental outcomes. In different circumstances, they found beforehand unidentified emission strains within the Fe X spectrum, which can have to be added to CHIANTI to enhance future predictions.