→ SolRaT
SolRaT
SolRaT (Solar Radiative Transfer) is a forward modeling code, implementing the non-LTE statistical equilibrium and radiative transfer equations within the multi-term atom model.
Figure: Model of He I D3 emission in a limb event under different magnetic fields
SolRaT solves the statistical equilibrium and radiative transfer equations for magnetic fields of arbitrary strengths within the intermediate Paschen-Back regime.
Figure: Magnetic splitting of the hydrogen 2p term: from linear Zeeman to complete Paschen-Back effect
SolRaT is designed as a flexible codebase supporting quick modifications and prototyping. The meta-language used in SolRaT allows to modify the model assumptionsto adjust for different observational material.
Figure: Ni I 5436 line: radiative transfer is solved assuming LTE atomic level populations
SolRaT uses Faraday-Voigt profiles to allow modeling different line broadening mechanisms.
Figure: Sample complex Faraday-Voigt profiles
SolRaT uses the DELO integration method to calculate the emerging Stokes profiles from the radiative transfer coefficients. Currently, SolRaT only supports atmosphere models consisting from constant-property slabs; more general models with continuous changes of thermodynamical parameters will be added in the upcoming releases.
Figure: Comparison of the DELO solution and the finite-difference 20-step integration
SolRaT allows to use the parametrized radiation tensor J accounting for the anisotropy of the illuminating light to model the corresponding non-LTE effects.
Figure: n and w parameters defining the J00 and J20 radiation tensor components; J20 for different transitions in the He I atom
SolRaT has been extensively tested against other codes including HAZEL2, and against many analytical solutions under various additional simplifying approximations.
Figure: Comparison of the spontaneous emission against an analytical solution in the case of zero magnetic field
SolRaT runs on Windows, Linux, and any other system that fully supports python 3.
Journal article and detailed documentation are pending.
Until then, if SolRaT has found use in your research, please cite it as:
Yakovkin I. I. SolRaT (2023) [computer software]. Retrieved from https://www.yakovkinii.com/solrat/
Copyright (C) 2023 — 2026, Ivan I. Yakovkin. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL Ivan I. Yakovkin BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Except as contained in this notice, the name of Ivan I. Yakovkin shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from Ivan I. Yakovkin.