Skip to Main content Skip to Navigation
Journal articles

Strong Perpendicular Velocity-space Diffusion in Proton Beams Observed by Parker Solar Probe

Abstract : Abstract The SWEAP instrument suite on Parker Solar Probe (PSP) has detected numerous proton beams associated with coherent, circularly polarized, ion-scale waves observed by PSP’s FIELDS instrument suite. Measurements during PSP Encounters 4−8 revealed pronounced complex shapes in the proton velocity distribution functions (VDFs), in which the tip of the beam undergoes strong perpendicular diffusion, resulting in VDF level contours that resemble a “hammerhead.” We refer to these proton beams, with their attendant “hammerhead” features, as the ion strahl. We present an example of these observations occurring simultaneously with a 7 hr ion-scale wave storm and show results from a preliminary attempt at quantifying the occurrence of ion-strahl broadening through three-component ion VDF fitting. We also provide a possible explanation of the ion perpendicular scattering based on quasilinear theory and the resonant scattering of beam ions by parallel-propagating, right circularly polarized, fast magnetosonic/whistler waves.
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03578713
Contributor : Thierry Dudok de Wit Connect in order to contact the contributor
Submitted on : Thursday, February 17, 2022 - 2:53:26 PM
Last modification on : Tuesday, May 10, 2022 - 3:24:58 PM
Long-term archiving on: : Wednesday, May 18, 2022 - 7:04:22 PM

File

Verniero_2022_ApJ_924_112.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

B. Chandran, D. Larson, K. Paulson, B. Alterman, S. Badman, et al.. Strong Perpendicular Velocity-space Diffusion in Proton Beams Observed by Parker Solar Probe. The Astrophysical Journal, American Astronomical Society, 2022, 924 (2), pp.112. ⟨10.3847/1538-4357/ac36d5⟩. ⟨insu-03578713⟩

Share

Metrics

Record views

45

Files downloads

11