The effects of plasma source on adiabatic electron acceleration at dipolarization fronts
Particle acceleration is a commonly observed phenomenon at dipolarization fronts. Many studies have attempted to determine the acceleration mechanism, with betatron acceleration being a major candidate. In previous work, we attempted to match the observed change in electron energy to the change pred...
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Frontiers Media S.A.
2025-01-01
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| author | S. N. F. Chepuri A. N. Jaynes J. Joseph D. L. Turner C. Gabrielse I. J. Cohen D. N. Baker B. H. Mauk T. Leonard J. F. Fennell |
| author_facet | S. N. F. Chepuri A. N. Jaynes J. Joseph D. L. Turner C. Gabrielse I. J. Cohen D. N. Baker B. H. Mauk T. Leonard J. F. Fennell |
| author_sort | S. N. F. Chepuri |
| collection | DOAJ |
| description | Particle acceleration is a commonly observed phenomenon at dipolarization fronts. Many studies have attempted to determine the acceleration mechanism, with betatron acceleration being a major candidate. In previous work, we attempted to match the observed change in electron energy to the change predicted by betatron acceleration, but found that although this worked in some cases, overall betatron acceleration alone could not describe the observed energy spectrum changes. In this work, we attempted to study whether ion acceleration showed similar behavior and whether a quasi-adiabatic correction would be more accurate. On average the betatron acceleration equation overestimated the observed acceleration and the quasi-adiabatic correction did not account for the difference, although there are limitations to this study due to data fidelity. We then turned to study whether our assumptions about the source population having the same phase space density as the cold pre-existing background population in the plasma sheet are valid. We indirectly studied this by comparing the relative abundances of O+ and He++ as proxies for ionospheric and solar wind populations respectively. We found the betatron acceleration equation method performs slightly better when there is a stronger ionospheric component. This suggests that when more plasma containing O+ is present in the dipolarization front, it indicates that the source population is more local and therefore this method of using betatron acceleration is more valid. |
| format | Article |
| id | doaj-art-93dcdbbfdc6d43c481bc655aa285f115 |
| institution | Kabale University |
| issn | 2296-987X |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj-art-93dcdbbfdc6d43c481bc655aa285f1152025-01-13T06:11:03ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2025-01-011110.3389/fspas.2024.15285011528501The effects of plasma source on adiabatic electron acceleration at dipolarization frontsS. N. F. Chepuri0A. N. Jaynes1J. Joseph2D. L. Turner3C. Gabrielse4I. J. Cohen5D. N. Baker6B. H. Mauk7T. Leonard8J. F. Fennell9Department of Physics and Astronomy, University of Iowa, Iowa City, IA, United StatesDepartment of Physics and Astronomy, University of Iowa, Iowa City, IA, United StatesDepartment of Physics and Astronomy, University of Iowa, Iowa City, IA, United StatesThe Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United StatesThe Aerospace Corporation, El Segundo, CA, United StatesThe Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United StatesLaboratory of Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, United StatesThe Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United StatesCIRES, University of Colorado Boulder, Boulder, CO, United StatesThe Aerospace Corporation, El Segundo, CA, United StatesParticle acceleration is a commonly observed phenomenon at dipolarization fronts. Many studies have attempted to determine the acceleration mechanism, with betatron acceleration being a major candidate. In previous work, we attempted to match the observed change in electron energy to the change predicted by betatron acceleration, but found that although this worked in some cases, overall betatron acceleration alone could not describe the observed energy spectrum changes. In this work, we attempted to study whether ion acceleration showed similar behavior and whether a quasi-adiabatic correction would be more accurate. On average the betatron acceleration equation overestimated the observed acceleration and the quasi-adiabatic correction did not account for the difference, although there are limitations to this study due to data fidelity. We then turned to study whether our assumptions about the source population having the same phase space density as the cold pre-existing background population in the plasma sheet are valid. We indirectly studied this by comparing the relative abundances of O+ and He++ as proxies for ionospheric and solar wind populations respectively. We found the betatron acceleration equation method performs slightly better when there is a stronger ionospheric component. This suggests that when more plasma containing O+ is present in the dipolarization front, it indicates that the source population is more local and therefore this method of using betatron acceleration is more valid.https://www.frontiersin.org/articles/10.3389/fspas.2024.1528501/fullenergetic particlesdipolarization frontsadiabatic accelerationbetatron accelerationMMSmagnetotail |
| spellingShingle | S. N. F. Chepuri A. N. Jaynes J. Joseph D. L. Turner C. Gabrielse I. J. Cohen D. N. Baker B. H. Mauk T. Leonard J. F. Fennell The effects of plasma source on adiabatic electron acceleration at dipolarization fronts Frontiers in Astronomy and Space Sciences energetic particles dipolarization fronts adiabatic acceleration betatron acceleration MMS magnetotail |
| title | The effects of plasma source on adiabatic electron acceleration at dipolarization fronts |
| title_full | The effects of plasma source on adiabatic electron acceleration at dipolarization fronts |
| title_fullStr | The effects of plasma source on adiabatic electron acceleration at dipolarization fronts |
| title_full_unstemmed | The effects of plasma source on adiabatic electron acceleration at dipolarization fronts |
| title_short | The effects of plasma source on adiabatic electron acceleration at dipolarization fronts |
| title_sort | effects of plasma source on adiabatic electron acceleration at dipolarization fronts |
| topic | energetic particles dipolarization fronts adiabatic acceleration betatron acceleration MMS magnetotail |
| url | https://www.frontiersin.org/articles/10.3389/fspas.2024.1528501/full |
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