Uphill acceleration in a spatially modulated electrostatic field particle accelerator

• Autor(a) principal: Almansa, Ivanessa da Silveira
• Data de Publicação: 2018
• Outros Autores: Burton, David A., Cairns, R.A., Marini, Samuel, Peter, Eduardo Alcides, Rizzato, Felipe Barbedo, Russman, Felipe Boff
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/204117
• topic: Aceleradores de partículas; Simulação numérica; Ondas eletrostáticas

Spatially modulated electrostatic fields can be designed to efficiently accelerate particles by exploring the relationships between the amplitude, the phase velocity, the shape of the potential, and the initial velocity of the particle. The acceleration process occurs when the value of the velocity excursions of the particle surpasses the phase velocity of the carrier, as a resonant mechanism. The ponderomotive approximation based on the Lagrangian average is usually applied in this kind of system in non-accelerating regimes. The mean dynamics of the particle is well described by this approximation far from resonance. However, the approximation fails to predict some interesting features of the model near resonance, such as the uphill acceleration phenomenon. A canonical perturbation theory is more accurate in these conditions. In this work, we compare the results from the Lagrangian average and from a canonical perturbation theory, focusing in regions where the results of these two approaches differ from each other.