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Topanga: A kinetic ion plasma code for large-scale ionospheric simulations on magnetohydrodynamic timescales.
- Source :
-
Physics of Plasmas . Jan2024, Vol. 31 Issue 1, p1-22. 22p. - Publication Year :
- 2024
-
Abstract
- Topanga is a kinetic ion code developed for simulating large-scale plasma phenomena in the Earth's ionosphere on magnetohydrodynamic timescales. It is a domain-decomposed parallel code that runs on high-performance computing platforms. Features of Topanga include spherical geometry for simplified boundary conditions and computational efficiency; a hybrid plasma model with inertia-less fluid electrons, kinetic ions, and an electric field specified via an Ohm's law; a Maxwell-FDTD (finite difference time domain) plasma model which retains the displacement current in Maxwell's equations and models electron currents in the ionosphere with a tensor conductivity; sponge-layer boundary conditions for absorption of electromagnetic and plasma waves incident on the domain boundaries; and a novel mixed-implicit algorithm for evolving the EM fields inside the Maxwell-FDTD region that is stable over many orders of magnitude in the electron–ion collision frequency. We verify the numerical methods used in Topanga on a pair of test problems. The first test involves modeling a three-dimensional collisionless shock using the hybrid set of equations. The second test involves modeling a spherical TEM mode in vacuum using the Maxwell-FDTD set of equations. Finally, we demonstrate how using the combined set of hybrid and Maxwell-FDTD equations to model the Starfish Prime high-altitude nuclear test recovers a "missing" EM signal on the ground that is not present when using only the hybrid set of equations. The magnitude of this signal in the simulation containing the Maxwell-FDTD region agrees well with the E3a portion of the magnetohydrodynamic electromagnetic pulse from Starfish Prime. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 1070664X
- Volume :
- 31
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Physics of Plasmas
- Publication Type :
- Academic Journal
- Accession number :
- 175161585
- Full Text :
- https://doi.org/10.1063/5.0177132