Local and nonlocal parallel heat transport in general magnetic fields.

Area of Science:

• Plasma Physics
• Magnetohydrodynamics
• Computational Physics

Background:

• Numerical pollution in grid-based methods hinders accurate plasma transport studies.
• Understanding parallel transport is crucial for magnetized plasma behavior.

Purpose of the Study:

• To present a novel numerical approach for studying parallel transport in magnetized plasmas.
• To analyze temperature profiles and transport scaling in integrable and chaotic magnetic fields.
• To compare findings with existing quasilinear diffusion models.

Main Methods:

• A novel numerical method avoiding grid-based pollution.
• Application to both integrable and chaotic magnetic field configurations.
• Analysis of local and nonlocal parallel closures.

Main Results:

• Identified fractal 'devil's staircase' radial temperature profiles in weakly chaotic fields.
• Observed self-similar spatiotemporal temperature evolution in fully chaotic fields.
• Demonstrated stretched-exponential and algebraic scaling for local and nonlocal closures, respectively.
• Showcased incompatibility of effective radial heat transport with quasilinear diffusion.

Conclusions:

• The novel method accurately captures complex transport phenomena in magnetized plasmas.
• Results challenge the applicability of the quasilinear diffusion model for effective radial heat transport.
• The study provides new insights into temperature scaling and fractal structures in plasma physics.