| Autor: |
A. Fitzmaurice, J. F. Drake, M. Swisdak |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
The Astrophysical Journal, Vol 964, Iss 1, p 97 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
1538-4357 |
| DOI: |
10.3847/1538-4357/ad217f |
| Popis: |
The waves generated by high-energy proton and alpha particles streaming from solar flares into regions of colder plasma are explored using particle-in-cell simulations. Initial distribution functions for the protons and alphas consist of two populations: an energetic, streaming population represented by an anisotropic ( T _∥ > T _⊥ ), one-sided kappa function and a cold, Maxwellian background population. The anisotropies and nonzero heat fluxes of these distributions destabilize oblique waves with a range of frequencies below the proton cyclotron frequency. These waves scatter particles out of the tails of the initial distributions along constant-energy surfaces in the wave frame. Overlap of the nonlinear resonance widths allows particles to scatter into near-isotropic distributions by the end of the simulations. The dynamics of ^3 He are explored using test particles. Their temperatures can increase by a factor of nearly 20. Propagation of such waves into regions above and below the flare site can lead to heating and transport of ^3 He into the flare acceleration region. The amount of heated ^3 He that will be driven into the flare site is proportional to the wave energy. Using values from our simulations, we show that the abundance of ^3 He driven into the acceleration region should approach that of ^4 He in the corona. Therefore, waves driven by energetic ions produced in flares are a strong candidate to drive the enhancements of ^3 He observed in impulsive flares. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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