Relativistic particle acceleration in developing Alfv\'{e}n turbulence

TL;DR

This paper investigates a new particle acceleration mechanism in developing Alfvén turbulence within relativistic pair plasmas, revealing efficient acceleration and power-law energy distributions through wave-particle resonances.

Contribution

It introduces a novel acceleration process driven by relativistic resonance in evolving Alfvén turbulence, supported by analytical and simulation results.

Findings

Efficient particle acceleration leading to power-law energy spectra.

High-energy particles with large relativistic masses are preferentially accelerated.

Maximum attainable energy is analytically derived for wave-particle interactions.

Abstract

A new particle acceleration process in a developing Alfv\'{e}n turbulence in the course of successive parametric instabilities of a relativistic pair plasma is investigated by utilyzing one-dimensional electromagnetic full particle code. Coherent wave-particle interactions result in efficient particle acceleration leading to a power-law like energy distribution function. In the simulation high energy particles having large relativistic masses are preferentially accelerated as the turbulence spectrum evolves in time. Main acceleration mechanism is simultaneous relativistic resonance between a particle and two different waves. An analytical expression of maximum attainable energy in such wave-particle interactions is derived.