Proton Energization by Phase Steepening of Parallel-propagating Alfvenic Fluctuations

0543711 - ÚFA 2022 RIV US eng J - Journal Article
Gonzalez, C. A. - Tenerani, A. - Matteini, L. - Hellinger, Petr - Velli, M.
Proton Energization by Phase Steepening of Parallel-propagating Alfvenic Fluctuations.
Astrophysical Journal Letters. Roč. 914, č. 2 (2021), č. článku L36. ISSN 2041-8205. E-ISSN 2041-8213
Institutional support: RVO:68378289
Keywords : coherent structures * waves * plasma * evolution * discontinuities * instabilities * acceleration
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 8.811, year: 2021
Method of publishing: Open access
https://iopscience.iop.org/article/10.3847/2041-8213/ac097b

Proton energization at magnetic discontinuities generated by phase-steepened fronts of parallel-propagating, large-amplitude Alfvenic fluctuation is studied using hybrid simulations. We find that dispersive effects lead to the collapse of the wave via phase steepening and the subsequent generation of compressible fluctuations that mediate an efficient local energy transfer from the wave to the protons. Proton scattering at the steepened edges causes nonadiabatic proton perpendicular heating. Furthermore, the parallel electric field at the propagating fronts mediates the acceleration of protons along the mean field. A steady-state is achieved where the proton distribution function displays a field-aligned beam at the Alfven speed, and compressible fluctuations are largely damped. We discuss the implications of our results in the context of Alfvenic solar wind.
Permanent Link: http://hdl.handle.net/11104/0320883