Low-density laboratory spectra near the λ335 channel of the SDO/AIA instrument

Abstract

Aims. For a more complete interpretation of the extreme-ultraviolet (EUV) spectra of the solar corona, it is beneficial to acquire laboratory data of specific chemical elements obtained under coronal conditions. Methods. The EUV spectra of He, C, N, O, F, Ne, S, Ar, Fe, and Ni in a 30 Å wide wavelength interval near 335 have been excited in an electron beam ion trap. Results. We observe just under 200 lines, almost half of which are not yet identified and included in spectral models. Conclusions. Our data serve as a check on atomic databases that are used to interpret solar corona data such as collected by the Solar Dynamics Observatory spacecraft or the EUNIS instrument on sounding rockets. Our findings largely corroborate the databases. However, the accumulated flux of a multitude of mostly weak additional lines is comparable to that of various primary lines.