Eur. Phys. J. Plus (2014) 129: 145
https://doi.org/10.1140/epjp/i2014-14145-8

Regular Article

Stability analysis of a proton-beam driven fast ignition by using Nyquist criteria

¹ Physics Department, University of Guilan, P.O. Box 41335-1914, Rasht, Iran
² School of Physics, Damghan University, P.O. Box 36716-41167, Damghan, Iran

^* e-mail: skhoshbinfar@du.ac.ir

Received: 3 March 2014
Revised: 29 May 2014
Accepted: 12 June 2014
Published online: 8 July 2014

Abstract

Recent studies showed that in a proton-driven fast-ignition scenario, the stability of beam transport in plasma might be still a concern. In this paper, we have investigated the stability of incident proton beam in a hydrogen fusion plasma by Nyquist stability criteria. The advantage of the applied method is its graphical approach. Without engagement in a sophisticated numerical solution of beam-plasma stability boundaries through dispersion equation, we can draw a simple and robust alternative case. In the case of α = 0.1 (proton beam to plasma densities ratio), we have shown that the system would be stable for temperatures higher than 32 keV for proton beam. On the other hand, plasma electron temperatures close to keV yield a complete stabilization. Because of the sensitivity of stability conditions on the proton beam and plasma electron temperatures, stability zones have been derived for different α ratios in the {T _e , T _b } plane.