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Ion-Scale Wave Emission and Absorption from non-Maxwellian Velocity Distributions Measured by SWEAP/SPANi

ORAL

Abstract

Hot and tenuous plasmas have velocity distribution functions (VDFs) significantly different from simple analytical models. Characterizing how these differences impact wave damping and emission necessitates sophisticated methods for determining the associated dielectric plasma response. The Arbitrary Linear Plasma Solver (ALPS) is a tool for calculating such responses through the numerical integration of arbitrary gyrotropic VDFs, rather than using a prescribed analysis model for the VDF. We consider dispersion relations calculated using ALPS for ion-scale waves derived using example VDFs from SPANi measurements during Parker Solar Probe's perihelion encounters 22 and 23. The selected VDFs highlight evince beam driven instabilities and the damping of ion-cyclotron and kinetic Alfven waves. The non-Maxwellian structures drive significant changes in the amount of energy absorbed by the charged particles or emitted into the electromagnetic waves, changing expected heating rates from these waves in the inner heliosphere.

Presenters

  • Kristopher G Klein

    University of Arizona, University of Arizona, Tucson

Authors

  • Kristopher G Klein

    University of Arizona, University of Arizona, Tucson

  • Davin Larson

    Space Science Laboratory

  • Roberto Livi

    Space Science Laboratory

  • Mihailo M Martinovic

    University of Arizona

  • Ali Rahmati

    Space Science Laboratory

  • Niranjana Shankarappa

    University of Arizona

  • Michael L Stevens

    CFA

  • Daniel Verscharen

    University College London