Year: 2025
Type: article
Abstract: Many plasma systems, from pulsar magnetospheres to magnetic confinement devices, are highly magnetised. Simultaneously these myriad of plasma environments are often sufficiently tenuous and hot to be best described by kinetic theory and the full six dimensional Boltzmann-Maxwell system of equations, thus making these systems computationally demanding to model. To facilitate new kinetic models of magnetised plasmas, I will discuss a recent innovation which separates the parallel and perpendicular dynamics starting from the kinetic equation while staying agnostic to the inclusion of effects important to consider in diverse environments, such as strong flows in certain fusion reactors, relativistic energies in astrophysical plasmas, or complex boundary conditions and geometry in lab plasma modeling. The key component of the derivation lies in a spectral expansion of only the perpendicular degrees of freedom, analogous to spectral methods which have grown in popularity in recent years for gyrokinetics, while retaining the complete dynamics parallel to the magnetic field. We thus leverage our intuition that a magnetised plasma’s motion is different parallel and perpendicular to the magnetic field, allowing for the treatment of complex phase space dynamics parallel to the magnetic field but at reduced computational cost. The utility of this approach will be demonstrated with a classical benchmark: magnetic reconnection, but in regimes beyond what typical reduced models can capture and culminating in the application of the model to flux rope merging experiments at the Large Plasma Device at UCLA. We will conclude with a look ahead to an additional use-case of this model in the machine learning era: a flexible-fidelity, cost-optimized kinetic model for pre-training and fine-tuning of plasma foundation models that can potentially further accelerate kinetic simulations in this large diversity of magnetised plasma systems.
Source: Journal of Plasma Physics
Authors: James Juno, Ammar Hakim, Jason M. TenBarge
Institutions: Princeton Plasma Physics Laboratory, Princeton University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,550
OpenAlex ID: W4414371209