Nonresonant Charged-Particle Acceleration by Electrostatic Waves Propagating across Fluctuating Magnetic Field

Area of Science:

• Plasma physics
• Astrophysics
• Space physics

Background:

• Charged particles are typically accelerated by resonant wave-particle interactions.
• Understanding nonresonant acceleration mechanisms is crucial for explaining energy transfer in plasmas.

Purpose of the Study:

• To demonstrate a nonresonant charged-particle acceleration mechanism.
• To explore particle acceleration in electrostatic waves across magnetic fields.

Main Methods:

• Investigating particle dynamics in the presence of electrostatic waves and magnetic field fluctuations.
• Analyzing the conditions under which adiabatic motion is disrupted.

Main Results:

• Particles are accelerated by electrostatic waves even when their velocities are much smaller than the wave phase velocity.
• Magnetic field fluctuations destroy the adiabaticity of particle motion, enabling nonresonant acceleration.
• Electrostatic waves are damped due to stochastic particle dynamics, even without Landau resonance.

Conclusions:

• A novel mechanism for nonresonant charged-particle acceleration by electrostatic waves is demonstrated.
• This mechanism accelerates particles that cannot be reached by resonant interactions.
• The simplicity of this acceleration scenario suggests broad applicability in various physical systems.