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T: Fachverband Teilchenphysik

T 80: Cosmic Rays IV

T 80.1: Vortrag

Donnerstag, 3. April 2025, 16:15–16:30, VG 3.102

Investigation of the Diffusion Tensor for Different Turbulence Levels and Rigidities in the Resonant Scattering Regime — •Jan-Niklas Bohnensack¹, Julia Becker Tjus^1,2,3, and Leander Schlegel^1,2 — ¹Theoretical Physics IV: Plasma-Astroparticle Physics, Faculty for Physics & Astronomy, Ruhr-Universität Bochum, D-44780 Bochum, Germany; Supported by SFB1491 — ²Ruhr Astroparticle And Plasma Physics Center (RAPP Center), Bochum, Germany — ³Department of Space, Earth and Environment, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden

The quasi-linear theory (QLT) describes the interactions between charged particles and astrophysical plasmas in the limit of b/B ≪ 1. The goal of the underlying thesis was to verify the QLT’s prediction that for small turbulence levels b/B, where b is turbulent magnetic field strength and B is the homogeneous magnetic field strength, the diffusion coefficient behaves like κ ∝ ρ^γ with γ = 1/3. This is currently only done with smaller statistics (number of propagated particles) due to technical restrictions. To overcome those restrictions a code was developed in the underlying thesis to utilize methods of parallelization that calculate the running diffusion coefficient from particles propagated with CRPropa faster. As part of this, an algorithm was created that can verify the convergence of the given running diffusion coefficient and can stop the simulations accordingly. With diffusion coefficients that were generated for a range of reduced rigidities and turbulence levels that lie in the Resonant Scattering Regime, the behavior of the index γ for smaller b/B according to the QLT was verified.

Keywords: Diffusion Tensor; Quasi Linear Theory; Simulation; CRPropa