86 citations · 725 across the 37 of their papers we have counts for
6 papers · 1 filter
Possible creation of net circular polarization and not only depolarization of spectral lines by isotropic collisions
Jiri Stepan, Sylvie Sahal-Brechot
We will show that isotropic collisions of electrons and protons with neutral hydrogen can lead to creation of net orientation of the atomic levels in the presence of a magnetic fie…
Hydrogen Balmer line formation in solar flares affected by return currents
Jiri Stepan, Jana Kasparova, Marian Karlicky +1
Aims. We investigate the effect of the electric return currents in solar flares on the profiles of hydrogen Balmer lines. We consider the monoenergetic approximation for the primar…
Generalized sqrt(epsilon)-law. The role of unphysical source terms in resonance line polarization transfer and its importance as an additional test of NLTE radiative transfer codes
Jiri Stepan, Veronique Bommier
Context. A derivation of a generalized sqrt(epsilon)-law for nonthermal collisional rates of excitation by charged perturbers is presented. Aims. Aim of this paper is to find a mor…
Polarization diagnostics of proton beams in solar flares
Jiri Stepan
We review the problem of proton beam bombardment of solar chromosphere considering the self-consistent NLTE polarized radiation transfer in hydrogen lines. Several observations ind…
Hydrogen H line polarization in solar flares. Theoretical investigation of atomic polarization by proton beams considering self-consistent NLTE polarized radiative transfer
Jiri Stepan, Petr Heinzel, Sylvie Sahal-Brechot
Context. We present a theoretical review of the effect of impact polarization of a hydrogen H line due to an expected proton beam bombardment in solar flares. Aims. Several obse…
Multigrid Methods for Polarized Radiative Transfer
Jiri Stepan
A new iterative method for non-LTE multilevel polarized radiative transfer in hydrogen lines is presented. Iterative methods (such as the Jacobi method) tend to damp out high-frequ…