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README.md

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 # plasma-analysis
-Repository containing code used to calculate field lines by massive parallel Runge-Kutta integration in CUDA and extract topological winding numbers from it.
+Repository containing code used to calculate field lines by massively parallel numerical integration using Runge-Kutta methods implemented in CUDA. And extract topological properties from the field line traces.
 
 Also contains some Python code to plot resulting data.
 
+The fields analysed contain field lines lying on toroidal surfaces. The program finds these tori (for an orientation of the main axis reasonably aligned with the z-axis) and calculates the winding number of the field lines relative to this torus.
+
 This code was used to produce a part of the data and plots for Smiet et al., _Resistive evolution of toroidal field distributions and their relation to magnetic clouds_ (2018, https://arxiv.org/abs/1812.00005) (accepted in [Journal of Plasma Physics](https://www.cambridge.org/core/journals/journal-of-plasma-physics)).