Role of reconnection in inertial kinetic-Alfvén turbulence
In a weakly collisional, low-electron-beta plasma, large-scale Alfvén turbulence transforms into inertial kinetic-Alfvén turbulence at scales smaller than the ion microscale (gyroscale or inertial scale). We propose that at such kinetic scales, the nonlinear dynamics tends to organize turbulent eddi...
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| Format: | Article |
| Language: | English |
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American Physical Society (APS)
2020
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| Online Access: | https://hdl.handle.net/1721.1/124293 |
| _version_ | 1811098294638608384 |
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| author | Boldyrev, Stanislav Gomes Loureiro, Nuno F |
| author2 | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Boldyrev, Stanislav Gomes Loureiro, Nuno F |
| author_sort | Boldyrev, Stanislav |
| collection | MIT |
| description | In a weakly collisional, low-electron-beta plasma, large-scale Alfvén turbulence transforms into inertial kinetic-Alfvén turbulence at scales smaller than the ion microscale (gyroscale or inertial scale). We propose that at such kinetic scales, the nonlinear dynamics tends to organize turbulent eddies into thin current sheets, consistent with the existence of two conserved integrals of the ideal equations, energy and helicity. The formation of strongly anisotropic structures is arrested by the tearing instability that sets a critical aspect ratio of the eddies at each scale a in the plane perpendicular to the guide field. This aspect ratio is defined by the balance of the eddy turnover rate and the tearing rate, and varies from (d [subscript]e / a)¹ / ² to d [subscript]e / a depending on the assumed profile of the current sheets. The energy spectrum of the resulting turbulence varies from k -⁸ / ³ to k -³ , and the corresponding spectral anisotropy with respect to the strong background magnetic field from [mathematical equation; see source] to [mathematical equation; see source]. |
| first_indexed | 2024-09-23T17:12:47Z |
| format | Article |
| id | mit-1721.1/124293 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T17:12:47Z |
| publishDate | 2020 |
| publisher | American Physical Society (APS) |
| record_format | dspace |
| spelling | mit-1721.1/1242932022-10-03T11:11:17Z Role of reconnection in inertial kinetic-Alfvén turbulence Boldyrev, Stanislav Gomes Loureiro, Nuno F Massachusetts Institute of Technology. Department of Nuclear Science and Engineering In a weakly collisional, low-electron-beta plasma, large-scale Alfvén turbulence transforms into inertial kinetic-Alfvén turbulence at scales smaller than the ion microscale (gyroscale or inertial scale). We propose that at such kinetic scales, the nonlinear dynamics tends to organize turbulent eddies into thin current sheets, consistent with the existence of two conserved integrals of the ideal equations, energy and helicity. The formation of strongly anisotropic structures is arrested by the tearing instability that sets a critical aspect ratio of the eddies at each scale a in the plane perpendicular to the guide field. This aspect ratio is defined by the balance of the eddy turnover rate and the tearing rate, and varies from (d [subscript]e / a)¹ / ² to d [subscript]e / a depending on the assumed profile of the current sheets. The energy spectrum of the resulting turbulence varies from k -⁸ / ³ to k -³ , and the corresponding spectral anisotropy with respect to the strong background magnetic field from [mathematical equation; see source] to [mathematical equation; see source]. NSF (Grant no. NSF PHY-1707272) NASA (Grant no. NASA 80NSSC18K0646) DOE (Grant no. DE-SC0018266) NSF CAREER (Award no. 1654168) NSF-DOE Partnership in Basic Plasma Science and Engineering (Award no. DE-SC0016215) 2020-03-24T19:23:13Z 2020-03-24T19:23:13Z 2019-08 2019-01 2020-02-24T17:59:38Z Article http://purl.org/eprint/type/JournalArticle 2643-1564 https://hdl.handle.net/1721.1/124293 Boldyrev, Stanislav, and Nuno F. Loureiro, "Role of reconnection in inertial kinetic-Alfvén turbulence." Physical review research 1 (2019): no. 012006. doi: 10.1103/PhysRevResearch.1.012006 ©2019 Author(s) en 10.1103/PHYSREVRESEARCH.1.012006 Physical review research Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf American Physical Society (APS) APS |
| spellingShingle | Boldyrev, Stanislav Gomes Loureiro, Nuno F Role of reconnection in inertial kinetic-Alfvén turbulence |
| title | Role of reconnection in inertial kinetic-Alfvén turbulence |
| title_full | Role of reconnection in inertial kinetic-Alfvén turbulence |
| title_fullStr | Role of reconnection in inertial kinetic-Alfvén turbulence |
| title_full_unstemmed | Role of reconnection in inertial kinetic-Alfvén turbulence |
| title_short | Role of reconnection in inertial kinetic-Alfvén turbulence |
| title_sort | role of reconnection in inertial kinetic alfven turbulence |
| url | https://hdl.handle.net/1721.1/124293 |
| work_keys_str_mv | AT boldyrevstanislav roleofreconnectionininertialkineticalfventurbulence AT gomesloureironunof roleofreconnectionininertialkineticalfventurbulence |