Particle accceleration in relativistically hot plasmas

ORAL

Abstract

In a weakly collisional plasma, particle interactions with turbulent fluctuations may lead to plasma heating. In recent numerical kinetic studies of relativistically hot plasmas, a power law tail was observed in the particle energy distribution function at ultra-relativistic energies (e.g., [1], [2]). In our previous work we proposed a phenomenological model of particle energization in which particles are magnetically trapped and accelerated in turbulent structures until they escape due to pitch angle scattering [3]. A formula for the power law observed in the particle energy pdf was derived and compared to the results of VPIC simulations. On this presentation we discuss this model and check it against a broader range of strengths of the background magnetic field relative to the magnetic fluctuations.

[1] - Comisso, L., Sironi, L. 2019, ApJ, 886, 122.

[2] - Zhdankin, V., Uzdensky, D. A., Werner, G. R., Begelman, M. C. 2019, PhRvL, 122, 055101.

[3] - Vega, C., Boldyrev, S., Roytershteyn, V., & Medvedev, M. 2022, ApJL, 924, L19.

*The work of CV and SB was partly supported by NSF Grant PHY-2010098, by NASA Grant 80NSSC18K0646, and by the Wisconsin Plasma Physics Laboratory (US Department of Energy Grant DE-SC0018266). VR was partially supported by NSF/DOE Partnership in Basic Plasma Science and Engineering through grant DE-SC0019315 and by NASA grant 80NSSC21K1692. Computational resources were provided by the Texas Advanced Computing Center at the University of Texas at Austin (XSEDE Allocations No. TG-PHY110016 and TG-ATM180015) and by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center.

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Presenters

  • Cristian S Vega

    • Univerdity of Wisconsin - Madison

Authors

  • Cristian S Vega

    • Univerdity of Wisconsin - Madison

  • Stanislav A Boldyrev

    • University of Wisconsin - Madison

  • Vadim S Roytershteyn

    • Space Science Institute