Influence of boundary condition on ion energy distribution function
Résumé
A two stream instability which is named the ion-ion instability is excited by coupling between the ion acoustic mode and the slow ion beam mode. It is well known that this instability goes into turbulent state. However, imposing boundary conditions reduces degrees of freedom of the instability and the chaotic oscillations are observed. Furthermore, it is revealed that the ion-ion instability saturates due to the particle trapping effect. In this paper, it is shown that the growth-rate of the instability with the boundary condition is lowered by a numerical calculation of non local dispersion relation. It is also shown that the ion energy distribution function is influened by the boundary condition.