Heating of a dense plasma using an intense, relativistic electron beam

Abstract

We report observations of heating of a dense (∼1017 cm−3) plasma using a 3-MeV electron beam with a current density of 5×105 A/cm2. The measured, strong dependence of heating on beam transverse temperature and the short saturation distance (<4 cm) are evidence that the beam-to-plasma energy transfer takes place via a fast growing microinstability such as the relativistic electron-electron two stream.

Creation and characterization of vortex clusters in atomic Bose-Einstein condensates

“…This phenomenon is established in classical fluids and is thought to be the mechanism responsible for Jupiter's great red spot [13,14]. The concept of an inverse energy cascade was introduced by Onsager [15] for a point-vortex gas consisting of many many vortices, where it was found clusters of like-signed point vortices have a negative temperature (further detail can be found in subsequent analyses [16,17]). Beyond the seminal work of Onsager, there is no fundamental theory that exists for small systems of vortices.…”

Observations of low-frequency oscillations during relativistic-electron-beam-plasma interactions

“…Two-stream instability between the beam electrons and the plasma electrons occurs during beam propagation in a plasma, giving rise to large-amplitude Langmuir waves at saturation. This instability is the primary mechanism for plasma heating if the beam is launched in a pre-ionized plasma (Thode 1976;Montgomery et al 1981;Gupta, Vijayan & Rohatgi 1988). However, if the plasma is produced in the ambient neutral gas by the beam itself, the two-stream instability is the main mechanism resulting in current gain at sub-torr gas pressures (Chambers 1979;.…”