Is Ni I 676.8 Nm line affected by electron beams in flaring atmospheres ?

V. V. Zharkova, A. G. Kosovichev

Research output: Contribution to journalConference articlepeer-review

5 Scopus citations


Non-LTE simulations for a model Ni I atom in the ambient plasma with solar element abundances are carried out in order to investigate the effects of electron beams on the resulting Ni I 676.8 nm emission during solar flares. The Ni I 676.8 nm line profiles, source functions and departure coefficients were calculated for a period of 10 s after an injection of beams with a variety of their initial parameters. The Ni I 676.8 nm line was found to decrease its depth in the core by about 30% in response to the increase of hydrodynamic heating of the atmosphere during the electron beam precipitation. At the maximum electron flux (6 s in our models), the line profile changes to emissive and stays as such for several seconds returning to the normal absorption profile after the beam is switched off (10 s). Therefore, the line measurements within a timescale of 1 min or longer are more likely not to be strongly affected by the line inversion while more precise (within seconds) temporal measurements on Ni 676.8 nm line profiles of the impulsive phase of flares have to be carefully investigated.

Original languageEnglish (US)
Pages (from-to)1031-1034
Number of pages4
JournalEuropean Space Agency, (Special Publication) ESA SP
Issue number506 II
StatePublished - Dec 2002
Externally publishedYes
EventThe 10th European Solar Physics Meeting; Solar Variability: From Core to Outer Frontiers - Prague, Czech Republic
Duration: Sep 9 2002Sep 14 2002

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Space and Planetary Science


  • Electron beam
  • Non-thermal ionization
  • Radiative transfer
  • Solar flares
  • Sun


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