Breakdown of the ponderomotive approximation as an acceleration mechanism in wave-particle nonlinear dynamics

• Autor(a) principal: Marini, Samuel
• Data de Publicação: 2017
• Outros Autores: Peter, Eduardo Alcides, Oliveira, Glaucius Iahnke de, Rizzato, Felipe Barbedo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/184778
• topic: Ondas eletromagnéticas; Simulação numérica; Dinâmica não-linear

In the present analysis, we study the dynamics of charged particles submitted to the action of slowly modulated electromagnetic carrier waves. While the velocity of the particles remains smaller than the carrier’s phase-velocity, their dynamics is well described by a refined ponderomotive approach. The ponderomotive approach has its own validity limits well established, beyond which particles are resonantly trapped by the carrier waves. We show that under adequate conditions, the trapping mechanism places particles at an optimal relative phase with respect to the carrier for maximum acceleration. In addition to the analytical approach involved in the ponderomotive description, we use numerical simulations to validate the corresponding dynamics as well as to explore various features of the resonant trapping and acceleration.