Journal article
Velocity-space Origins of the Pressure–Strain Interaction in Multipopulation Distributions and Its Application to Magnetic Reconnection
The Astrophysical journal, Vol.1005(2), 166
07/10/2026
DOI: 10.3847/1538-4357/ae75e9
Abstract
A forefront research question is how energy evolves in weakly collisional plasmas for which departures from local thermodynamic equilibrium (LTE) are significant. The standard approach is studying the terms in the non-LTE energy evolution equation derived by taking the second moment of the Boltzmann equation, but the resultant fluid metrics do not retain information about which particles at which velocities drive energy evolution. A widely studied channel for internal energy density evolution is the pressure–strain interaction. Here, we employ the kinetic pressure–strain, a phase-space diagnostic whose velocity-space integral recovers the pressure–strain interaction to disambiguate the contributions to the pressure–strain interaction from disparate particle populations in composite phase-space densities. We develop phase-space analogs of the pressure–strain interaction decompositions to provide the phase-space origins of normal versus sheared flow. We introduce the “kinetic strain-rate” tensor, the phase-space analog of the strain-rate tensor, which we argue is needed to interpret the phase-space origins of the pressure–strain interaction. To demonstrate the utility of these quantities, we investigate them for composite electron distributions near the electron diffusion region in two-dimensional particle-in-cell simulations of antiparallel symmetric magnetic reconnection. We find that the phase-space-based diagnostics isolate the roles of distinct populations. These results contribute to a growing body of work providing new methods for quantifying phase-space energy evolution for a broad array of processes, from magnetic reconnection to collisionless shocks and turbulence, opening new pathways for answering longstanding problems of particle energization in weakly collisional plasmas.
Details
- Title: Subtitle
- Velocity-space Origins of the Pressure–Strain Interaction in Multipopulation Distributions and Its Application to Magnetic Reconnection
- Creators
- M. Hasan Barbhuiya - Clemson UniversityPaul A Cassak - Clemson UniversitySarah Conley - Bates CollegeJulia E Stawarz - Northumbria UniversityEmily Lichko - Plasma (Russia)Jason M TenBarge - Princeton UniversityJames Juno - Princeton Plasma Physics LaboratoryJason R Shuster - University of New Hampshire at ManchesterGregory G Howes - University of IowaSubash Adhikari - University of Delaware
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.1005(2), 166
- DOI
- 10.3847/1538-4357/ae75e9
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- IOP Publishing
- Grant note
- National Aeronautics and Space Administration (NASA): 80NSSC24K0172 U.S. Department of Energy (DOE) National Science Foundation (NSF): PHY-2108834PHY-2108834 Royal Society (The Royal Society): URF\R\251029
We gratefully acknowledge support from NASA grants 80NSSC24K0172 (P.A.C.), 80NSSC19M0146 (P.A.C.), 80NSSC24K0552 (G.G.H.), and 80NSSC23K0099 (J.M.T.), NSF grant PHY-1804428 (P.A.C.), DOE grant DE-SC0020294 (P.A.C.), and Royal Society University Research Fellowship awards URF\R\251029 and URF\R1\201286 (J.E.S.). This research was partially supported by the International Space Science Institute (ISSI) in Bern, through ISSI International Team Project 23-588 ("Unveiling Energy Conversion and Dissipation in Non-Equilibrium Space Plasmas"). This research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under Contract DE-AC02-05CH11231 using NERSC Award FES-ERCAP0027083. S.A. was partially supported by the U.S. National Science Foundation award PHY-2108834, through the NSF/DOE Partnership in Basic Plasma Science and Engineering and NASA MMS Mission Theory, Modeling and Data Analysis Program 80NSSC19K0565
- Language
- English
- Date published
- 07/10/2026
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9985179854002771
Metrics
1 Record Views