Helium in solar flares

Solar flares are the most energetical process in the Solar system and massive amount of energy is released during such eruptions in the form of heat, radiation and accelerated particles. Propagation of electron beam in the solar atmosphere is described by the re- sults of the numerical code RADYN, whose results were used in this thesis for studying radiation losses of helium transitions and subsequent determination, if and which helium transitions are important in processes in the solar atmosphere during a solar flare. It was determined by studying height dependency of the radiation losses for various parameter combinations of the electron beam and various times of electron beam propagation in the solar atmosphere that radiation losses of helium transitions are important for modelling of solar flares. Among the most important helium transitions are the transitions 10830.29 Å, 20580.82 Å, 227.84 Å, 503.98 Å and 303.78 Å.