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This content will become publicly available on April 21, 2023

Title: Pressure–Strain Interaction as the Energy Dissipation Estimate in Collisionless Plasma
The dissipative mechanism in weakly collisional plasma is a topic that pervades decades of studies without a consensus solution. We compare several energy dissipation estimates based on energy transfer processes in plasma turbulence and provide justification for the pressure–strain interaction as a direct estimate of the energy dissipation rate. The global and scale-by-scale energy balances are examined in 2.5D and 3D kinetic simulations. We show that the global internal energy increase and the temperature enhancement of each species are directly tracked by the pressure–strain interaction. The incompressive part of the pressure–strain interaction dominates over its compressive part in all simulations considered. The scale-by-scale energy balance is quantified by scale filtered Vlasov–Maxwell equations, a kinetic plasma approach, and the lag dependent von Kármán–Howarth equation, an approach based on fluid models. We find that the energy balance is exactly satisfied across all scales, but the lack of a well-defined inertial range influences the distribution of the energy budget among different terms in the inertial range. Therefore, the widespread use of the Yaglom relation in estimating the dissipation rate is questionable in some cases, especially when the scale separation in the system is not clearly defined. In contrast, the pressure– strain interaction balances exactly the dissipation rate at kinetic scales regardless of the scale separation
Authors:
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Award ID(s):
2108834
Publication Date:
NSF-PAR ID:
10329562
Journal Name:
The Astrophysical journal
Volume:
929
Page Range or eLocation-ID:
142
ISSN:
0004-637X
Sponsoring Org:
National Science Foundation
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