The Effect of Alternating Magnetic Field on Acceleration of Charged Particles

TL;DR

This paper investigates how a time-varying magnetic field influences charged particle acceleration, showing that synchrotron radiation effects keep the diffusion coefficient at the Fermi value and deriving conditions for effective acceleration.

Contribution

It provides a self-consistent formulation of wave-particle interactions in a periodically varying magnetic field, including the effects of synchrotron radiation and instability-driven scattering.

Findings

Diffusion coefficient remains at Fermi value when accounting for synchrotron radiation.

Derived minimum particle concentration for effective acceleration via cyclotron instability.

Solved the wave-particle spectrum self-consistently in a time-varying magnetic field.

Abstract

The self-consistent problem of the wave and particle spectrum is formulated and solved for acceleration of particles in a homogeneous magnetic field that varies periodically with time. It follows from the obtained solutions that when account is taken of the synchrotron radiation, the diffusion coefficient Do of ultrarelativistic electrons does not differ from the Fermi value. An expression is obtained for the minimum concentration of the accelerated particles, at which the cyclotron instability ensures the scattering necessary for effective acceleration.