Alpha Core–Beam Origin in Low-β Solar Wind Plasma: Insights from Fully Kinetic Simulations
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Discipline
Physical sciences
Subject
Plasma physics
Space plasmas
Solar wind
Alfven waves
Plasma astrophysics
Audience
Scientific
Date
2026Metadata
Show full item recordDescription
In situ observations of the fast solar wind in the inner heliosphere show that minor ions and ion subpopulations often exhibit distinct drift velocities. Both alpha particles and proton beams stream at speeds that rarely exceed the local Alfvén speed relative to the core protons, suggesting the presence of instabilities that constrain their maximum drift. We aim to propose a mechanism that generates an alpha-particle beam through nonlinear Landau damping, primarily driven by the relative super-Alfvénic drift between protons and alpha particles. To investigate this process, we perform one-dimensional, fully kinetic particle-in-cell simulations of a nonequilibrium multispecies plasma complemented by its linear theory to validate the model during the linear phase. Our results provide clear evidence that the system evolves by producing an alpha-particle beam, thereby suggesting a local mechanism for alpha-beam generation via nonlinear Landau damping.
Citation
Pezzini, L.; Bacchini, F.; Zhukov, A.N.; Arró, G.; López, R.A. (2026). Alpha Core–Beam Origin in Low-β Solar Wind Plasma: Insights from Fully Kinetic Simulations. , The Astrophysical Journal, Vol. 997, Issue 2, A158, DOI: 10.3847/1538-4357/ae27a3.Identifiers
url:
Type
Article
Peer-Review
Yes
Language
eng
