Investigating particle acceleration dynamics in interpenetrating magnetized collisionless super-critical shocks

TL;DR

This study investigates particle acceleration in interpenetrating super-critical magnetized collisionless shocks, aiming to observe the phase-locking effect and its impact on ion energy spectra relevant to astrophysical phenomena.

Contribution

It introduces measurements of particle acceleration in interpenetrating super-critical shocks to observe the phase-locking effect, expanding understanding beyond single shock interactions.

Findings

Phase-locking effect significantly boosts ion energy spectra.

Interpenetrating super-critical shocks enhance particle acceleration.

Results could impact models of cosmic ion energization.

Abstract

Colliding collisionless shocks appear in a great variety of astrophysical phenomena and are thought to be possible sources of particle acceleration in the Universe. We have previously investigated particle acceleration induced by single super-critical shocks (whose magnetosonic Mach number is higher than the critical value of 2.7) (Yao et al. 2021, 2022), as well as the collision of two sub-critical shocks (Fazzini et al. 2022). Here, we propose to make measurements of accelerated particles from interpenetrating super-critical shocks to observe the ''phase-locking effect'' (Fazzini et al. 2022) from such an event. This effect is predicted to significantly boost the energy spectrum of the energized ions compared to a single supercritical collisionless shock. We thus anticipate that the results obtained in the proposed experiment could have a significant impact on our understanding of one type of primary source (acceleration of thermal ions as opposed to secondary acceleration mechanisms of already energetic ions) of ion energization of particles in the Universe.