Modelling magnetised medium particle transport in the guiding centre limit with GEANT4

Autor(es)

Tuneu, J. ^[1] ; Gimenez de Castro, G. ^{[2, 1]} ; Szpigel, S. ^[1] ; MacKinnon, A. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Presbiteriana Mackenzie, Ctr Radio Astron & Astrofis Mackenzie, Sao Paulo - Brazil

^[2] CONICET UBA, Inst Astron & Fis Espacio, Buenos Aires, DF - Argentina

^[3] Univ Glasgow, Sch Phys & Astron, Glasgow, Lanark - Scotland

• Tipo de documento: Artigo Científico
• Fonte: Astronomy & Astrophysics; v. 654, OCT 15 2021.
• Citações Web of Science: 0

Resumo

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. (AU)

• Processo FAPESP: 16/23428-4 - Simulações Monte Carlo de processos nucleares durante explosões solares em presença de campos magnéticos
• Beneficiário: Jordi Tuneu Serra
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 18/08180-1 - Simulações em Geant4 de processos nucleares em um plasma magneto-ativo durante explosões solares
• Beneficiário: Jordi Tuneu Serra
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 13/24155-3 - Diagnóstico de explosões solares em inédito intervalo espectral, de micro-ondas até frequências THz: desafios para interpretação (FLAT)
• Beneficiário: Carlos Guillermo Giménez de Castro
• Modalidade de apoio: Auxílio à Pesquisa - Temático