Plasma heating with a rotating relativistic electron beam. I. Return current processes

Relativistic particle acceleration in an electron-positron plasma with a relativistic electron beam

Results from three-dimensional electromagnetic particle simulations of an electron-positron plasma with a relativistic electron beam (y=2) are presented. As part of the initial conditions, a poloidal magnetic field is specified, consistent with the current carried by the beam electrons. The beam undergoes pinching oscillations due to the pressure imbalance. A transverse two-stream instability i...

Pulsed Electron-Beam Heating

A pulsed, 20 kv electron beam is focussed upon a vapor-deposited thermocouple, and the resulting temperature vs. time response is studied. The experimental data show much scatter, but are consistent with the theoretical prediction that the characteristic thermal response time T is proportional to d , where d is the beam diameter at the thermocouple. From these data, for the soft-glass substrate...

Multidimensional electron beam-plasma instabilities in the relativistic regime

Instabilities for a relativistic electron beam interacting with a laser-irradiated plasma.

The effects of a radiation field (RF) on the unstable modes developed in a relativistic electron beam-plasma interaction are investigated assuming that ω(0) > ω(p), where ω(0) is the frequency of the RF and ω(p) is the plasma frequency. These unstable modes are parametrically coupled to each other due to the RF and are a mix between two-stream and parametric instabilities. The dispersion equati...

Tokamak heating by relativistic electron beams

The use of relativistic electron beams for supplementary heating of tokamaks to ignition temperatures is discussed, under the assumption that they can be successfully injected. It is shown that if an electron beam with presentstate-of-the-art power, but longer pulse length, can be injected into an Ohmically pre-heated tokamak plasma, it transfers its energy to the plasma on a time-scale short e...