Bernstein wave propagating obliquely to the magnetic field is excited by a coaxial antenna in a streaming plasma and detected by the interferometer system, which shows that the dispersion relation for the wave is consistent with the theoretical result. The other wave-like signal with shorter 'wavelength' is observed only on the downstream of the exciting antenna and its 'phase velocity' is appr...

In this paper we describe the recent work at UCLA on the acceleration of externally injected electrons by a relativistic plasma wave. A two frequency laser was used to excite a plasma wave over a narrow range of static gas pressures close to resonance. Electrons with energies up to our detection limit of 9.1 MeV were observed when 2.1 MeV electrons were injected in the plasma wave. No accelerat...

A method for driving rotation and a countercurrent flow in a fully ionized plasma centrifuge is described. The rotation is produced by radiofrequency waves near the cyclotron resonance. The wave energy is transferred into potential energy in a manner similar to the α channeling effect. The countercurrent flow may also be driven by radiofrequency waves. By driving both the rotation and the flow ...

In the plasma beat wave acceleration scheme, the ponderomotive force of a two-frequency laser pulse resonantly drives a large amplitude (E≈3 GV/m) relativistic electrostatic plasma wave. The electro-static (es) wave does not couple to the vacuum modes and its energy is dissipated in the plasma. With a static magnetic field B0z applied perpendicularly to the laser beam propagation axis x, the tw...

We investigate the interaction of magnetohydrody-namic waves with plasma density inhomogeneities. Our numerical study of the full MHD equations shows that: (A) Plasma density inhomogeneities are a source of non-linear generation of transverse com-pressive waves by a plane Alfvén wave, and substantially enhance (by about a factor of 2) the generation of the longitudinal compressive waves. (B) At...

We report on some of the recent theoretical and computational results at UCLA and USC on plasma-based accelerator concepts. Topics discussed include beat-wave excitation from short-pulse lasers, self-trapped electron acceleration from self-modulational instabilities and wakefield excitation in preformed channels. INTRODUCTION For some time now plasma structures have been considered as the basis...

In situ particle acceleration is probably occur-ing in cluster radio haloes. This is suggested by the uniformity and extent of the haloes, given that spatial diffusion is slow and that radiative losses limit particle lifetimes. Stochastic acceleration by plasma turbulence is the most likely mechanism. Alfven wave turbulence has been suggested as the means of acceleration, but it is too slow to ...