Dynamics of electromagnetic two-stream interaction processes during longitudinal and transverse compression of an intense ion beam pulse propagating through background plasma

Abstract

To achieve maximum energy density, an intense ion beam must be compressed radially and longitudinally while its space-charge is neutralized by background plasma. An ion beam propagating through background plasma may be subject to the electrostatic two-stream instability and the electromagnetic Weibel instability. The electrostatic two-stream instability may lead to longitudinal bunching of the beam pulse, and eventual longitudinal beam heating. Consequently, this could degrade the longitudinal compression of the beam pulse. Similarly, the electromagnetic Weibel instability may cause transverse filamentation of the beam, which may degrade transverse compression. In this paper, we use an eikonal (Wentzel–Kramer–Brillouin, WKB) approach to analyze the space–time development of the two-stream and Weibel instabilities during transverse and longitudinal compression of an intense heavy ion beam pulse propagating through neutralizing background plasma.