Longitudinal instability of the proton ignitor beam in a contaminated DT plasma

Abstract

In this study, in the framework of hydrodynamics and kinetic models, the growth rate of longitudinal instability in a proton beam-DT fuel plasma system with carbon contamination has been numerically studied. Accordingly, the effect of the relative density of impurity ion on the position and height of the two-stream peak has been investigated. It is observed that in the cold fluid model of diluted incident beam regime, an increase in the relative concentration of carbon ions in the admissible ignition interval decreases the instability rapidly. This feature is more noticeable in the context of the kinetic model. Finally, it is concluded that the thermal effects of the igniting plasma, as well as the small fraction of carbon impurities mixed in DT plasma, will suppress the two-stream peak in the proton beam transport faster than usual.