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Title: Dissipation and particle energization in moderate to low beta turbulent plasma via PIC simulations

Here, we simulate decaying turbulence in electron-positron pair plasmas using a fully-kinetic particle-in-cell (PIC) code. We run two simulations with moderate-to-low plasma β (the ratio of thermal pressure to magnetic pressure). The energy decay rate is found to be similar in both cases. The perpendicular wave-number spectrum of magnetic energy shows a slope between $${k}_{\perp }^{-1.3}$$ and $${k}_{\perp }^{-1.1}$$, where the perpendicular (⊥) and parallel (∥) directions are defined with respect to the magnetic field. The particle kinetic energy distribution function shows the formation of a non-thermal feature in the case of lower plasma β, with a slope close to E-1. The correlation between thin turbulent current sheets and Ohmic heating by the dot product of electric field (E) and current density (J) is investigated. By heating the parallel E∥ centerdot J∥ term dominates the perpendicular E⊥ centerdot J⊥ term. Regions of strong E∥ centerdot J∥ are spatially well-correlated with regions of intense current sheets, which also appear correlated with regions of strong E∥ in the low β simulation, suggesting an important role of magnetic reconnection in the dissipation of low β plasma turbulence.
Authors:
 [1] ; ORCiD logo [2] ; ORCiD logo [2] ;  [3]
  1. Katholieke Univ., Leuven (Belgium). Center for Mathathematical Plasma Astrophysics
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of Alabama, Huntsville, AL (United States)
Publication Date:
Report Number(s):
LA-UR-16-26433
Journal ID: ISSN 1742-6588; TRN: US1800213
Grant/Contract Number:
AC52-06NA25396; AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Journal of Physics. Conference Series
Additional Journal Information:
Journal Volume: 837; Journal ID: ISSN 1742-6588
Publisher:
IOP Publishing
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Astronomy and Astrophysics
OSTI Identifier:
1411345