Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration
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 represente...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad217f |
| _version_ | 1797255707425243136 |
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| author | A. Fitzmaurice J. F. Drake M. Swisdak |
| author_facet | A. Fitzmaurice J. F. Drake M. Swisdak |
| author_sort | A. Fitzmaurice |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-24T22:10:08Z |
| format | Article |
| id | doaj.art-2f48466d534941879e8f61d40b126c31 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-24T22:10:08Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-2f48466d534941879e8f61d40b126c312024-03-20T09:44:31ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0196419710.3847/1538-4357/ad217fWave Generation by Flare-accelerated Ions and Implications for 3He AccelerationA. Fitzmaurice0J. F. Drake1https://orcid.org/0000-0002-9150-1841M. Swisdak2https://orcid.org/0000-0002-5435-3544Department of Physics, University of Maryland , College Park, MD 20740, USA; Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, MD 20740, USAInstitute for Research in Electronics and Applied Physics, University of Maryland , College Park, MD 20740, USA; Department of Physics, the Institute for Physical Science and Technology and the Joint Space Institute, University of Maryland , College Park, MD 20740, USADepartment of Physics, University of Maryland , College Park, MD 20740, USA; Institute for Research in Electronics and Applied Physics, University of Maryland , College Park, MD 20740, USAThe 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.https://doi.org/10.3847/1538-4357/ad217fSolar energetic particlesSolar physicsSolar flaresSpace plasmas |
| spellingShingle | A. Fitzmaurice J. F. Drake M. Swisdak Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration The Astrophysical Journal Solar energetic particles Solar physics Solar flares Space plasmas |
| title | Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration |
| title_full | Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration |
| title_fullStr | Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration |
| title_full_unstemmed | Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration |
| title_short | Wave Generation by Flare-accelerated Ions and Implications for 3He Acceleration |
| title_sort | wave generation by flare accelerated ions and implications for 3he acceleration |
| topic | Solar energetic particles Solar physics Solar flares Space plasmas |
| url | https://doi.org/10.3847/1538-4357/ad217f |
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