Modelling magnetised medium particle transport in the guiding centre limit with GEANT4
Tipo
Artigo
Data de publicação
2021
Periódico
Astronomy and Astrophysics
Citações (Scopus)
0
Autores
Tuneu J.
De Castro G.G.
Szpigel S.
Mackinnon A.
De Castro G.G.
Szpigel S.
Mackinnon A.
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Resumo
© ESO 2021.Monte Carlo codes are a standard tool for studying energetic particle propagation, secondary production, and radiation in astrophysical settings. In magnetised plasmas such as those found in solar active regions, the enormous disparity between particle gyroradii and system scales proves to be a major computational obstacle. To address this problem we have written a new module in Geant4 using the guiding centre (GC) approach in which the particle motion is averaged over a gyrofrequency. We describe the formulation and implementation of this method in particular dealing with the uncertainty in gyrophase so that particle velocities are well-defined for input to the modules handling reactions. As far as feasible, we compare the propagation and slowing down of primary protons, secondary particle production, and run times in the GC limit with the Newton-Lorentz approach, finding very good agreement between the two methods and orders of magnitude improvement in run times in the GC case. Finally, we present an illustrative solar physics application involving two interacting dipoles, which is only achievable using the GC approach.
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Assuntos Scopus
Astroparticle physics , Guiding centers , Method: numerical , Monte Carlo codes , Particle transport , Runtimes , Standard tools , Sun: particle emissions , Sun:flares , Sun:magnetic fields