Sub-ion scale current sheets in kinetic Alfvén wave turbulence

Fuente: arXiv
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Main Authors: Sharma, Johan, Kumar, Ch Akshath, Makwana, Kirit D., Parashar, Tulasi N, Satyasmita, Sruti
Format: Preprint
Published: 2026
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author Sharma, Johan
Kumar, Ch Akshath
Makwana, Kirit D.
Parashar, Tulasi N
Satyasmita, Sruti
author_facet Sharma, Johan
Kumar, Ch Akshath
Makwana, Kirit D.
Parashar, Tulasi N
Satyasmita, Sruti
contents 3D kinetic particle-in-cell (PIC) simulations are performed using the kinetic Alfvén wave (KAW) eigenvector relations from a two-fluid model as initial conditions, in order to study turbulent fluctuations and intermittent structures at sub-ion and electron scales. Simulations with different ion-to-electron mass ratios are set up to investigate the role of electron scales in the formation of intermittent structures. We analyze the current sheet structures that develop in these simulations. Two algorithms, namely Breadth-First Search (BFS) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN), are employed to determine the thickness, length, and width of the current sheets, and both methods are found to yield consistent results. The average current sheet thickness scales inversely with the square root of the ion-to-electron mass ratio, with values close to the electron skin depth ($d_e$), indicating the presence of electron-scale current sheets in the simulations. The widths and lengths of the current sheets show a weaker scaling with the mass ratio. The scale-dependent kurtosis reveals enhanced intermittency at electron scales, consistent with magnetosheath observations. Distributions of scale-dependent properties of the current sheets also align with the electron skin depth of the different simulations and they lie within ranges observed in kinetic scale solar wind turbulence. This study reveals the nature of sub-ion-scale current sheets in KAW turbulence and their role in dissipation.
format Preprint
id arxiv_https___arxiv_org_abs_2601_18131
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Sub-ion scale current sheets in kinetic Alfvén wave turbulence
Sharma, Johan
Kumar, Ch Akshath
Makwana, Kirit D.
Parashar, Tulasi N
Satyasmita, Sruti
Plasma Physics
Solar and Stellar Astrophysics
Computational Physics
Space Physics
3D kinetic particle-in-cell (PIC) simulations are performed using the kinetic Alfvén wave (KAW) eigenvector relations from a two-fluid model as initial conditions, in order to study turbulent fluctuations and intermittent structures at sub-ion and electron scales. Simulations with different ion-to-electron mass ratios are set up to investigate the role of electron scales in the formation of intermittent structures. We analyze the current sheet structures that develop in these simulations. Two algorithms, namely Breadth-First Search (BFS) and Density-Based Spatial Clustering of Applications with Noise (DBSCAN), are employed to determine the thickness, length, and width of the current sheets, and both methods are found to yield consistent results. The average current sheet thickness scales inversely with the square root of the ion-to-electron mass ratio, with values close to the electron skin depth ($d_e$), indicating the presence of electron-scale current sheets in the simulations. The widths and lengths of the current sheets show a weaker scaling with the mass ratio. The scale-dependent kurtosis reveals enhanced intermittency at electron scales, consistent with magnetosheath observations. Distributions of scale-dependent properties of the current sheets also align with the electron skin depth of the different simulations and they lie within ranges observed in kinetic scale solar wind turbulence. This study reveals the nature of sub-ion-scale current sheets in KAW turbulence and their role in dissipation.
title Sub-ion scale current sheets in kinetic Alfvén wave turbulence
topic Plasma Physics
Solar and Stellar Astrophysics
Computational Physics
Space Physics
url https://arxiv.org/abs/2601.18131