TITLE
	Enhanced acceleration of charged particles by crossing electromagnetic waves in a magnetized plasma, Resonant Moments Method	

AUTHOR
	Maxim PONOMARJOV

ABSTRACT 
	A mechanism for enhanced acceleration of charged particles in crossing 
	electromagnetic waves propagating at different angles with respect to an 
	external magnetic field is investigated. This mechanism consists in 
	introducing a lower amplitude secondary wave in order to improve the 
	parallel momentum transfer from the higher amplitude primary wave to charged 
	particles. 
	The theoretical analysis of the acceleration mechanism is based on the 
	Resonance Moments Method (RMM) in which the velocity distribution and its 
	moments are approximated by using an average over the resonant layers (RL) 
	only instead of a complete phase-space average. The quantities obtained 
	using this approach, referred to as Resonant Moments (RM), suggest the 
	existence of optimal angles of propagation for the primary and secondary 
	waves as long as the maximization of the parallel flux of charged particles 
	is considered. The secondary wave tends to maintain a pseudo-equilibrium 
	velocity distribution by continuously re-filling the RL. 
	Our suggestions are confirmed by direct numerical simulations of particle 
	trajectories based on a Hamiltonian dynamics, the parameters for these 
	simulations are relevant to magnetic plasma fusion experiments in electron 
	cyclotron resonance heating and electron acceleration in planetary 
	magnetospheres. Although measures of the distributions clearly show a 
	departure from a thermal equilibrium, the stochastization effect of the 
	secondary wave yields a clear increase (up to one order of magnitude) of the 
	average parallel velocity of the particles. It is a quite promising result 
	since the amplitude of the secondary wave is ten times lower the one of the 
	first wave.