Stabilizing the intensity of a wave amplified by a beam of particles

Romain Bachelard (1, 2) , Andrea Antoniazzi (3) , Cristel Chandre (1, 2) , Duccio Fanelli (3, 4) , Xavier Leoncini (1, 5, 2) , Michel Vittot (1, 2)

1 CPT - Centre de Physique Théorique - UMR 6207
2 CPT - Centre de Physique Théorique - UMR 7332
3 dip. energetica
4 dept cell molec. biology
5 PIIM - Physique des interactions ioniques et moléculaires

The intensity of an electromagnetic wave interacting self-consistently with a beam of charged particles as in a free electron laser, displays large oscillations due to an aggregate of particles, called the macro-particle. In this article, we propose a strategy to stabilize the intensity by re-shaping the macro-particle. This strategy involves the study of the linear stability (using the residue method) of selected periodic orbits of a mean-field model. As parameters of an additional perturbation are varied, bifurcations occur in the system which have drastic effect on the modification of the self-consistent dynamics, and in particular, of the macro-particle. We show how to obtain an appropriate tuning of the parameters which is able to strongly decrease the oscillations of the intensity without reducing its mean-value.

Mots clés: Wave/particle interactions; Control of chaos; Hamiltonian approach

Domaines: Dynamique Chaotique [nlin.CD]

Romain Bachelard, Andrea Antoniazzi, Cristel Chandre, Duccio Fanelli, Xavier Leoncini, et al.. Stabilizing the intensity of a wave amplified by a beam of particles. The European Physical Journal D : Atomic, molecular, optical and plasma physics, 2007, 42, pp.125. ⟨10.1140/epjd/e2006-00276-x⟩. ⟨hal-00092803⟩