Parametric Lower-Hybrid Instability Driven by Modulated Electron-Beam Injection

High-quality electron beams from beam-driven plasma accelerators by wakefield-induced ionization injection.

We propose a new and simple strategy for controlled ionization-induced trapping of electrons in a beam-driven plasma accelerator. The presented method directly exploits electric wakefields to ionize electrons from a dopant gas and capture them into a well-defined volume of the accelerating and focusing wake phase, leading to high-quality witness bunches. This injection principle is explained by...

Electron current drive by fusion-product-excited lower hybrid drift instability.

We present first principles simulations of the direct collisionless coupling of the free energy of fusion-born ions into electron current in a magnetically confined fusion plasma. These simulations demonstrate, for the first time, a key building block of some "alpha channeling" scenarios for tokamak experiments. Spontaneously excited obliquely propagating waves in the lower hybrid frequency ran...

Whistler Waves Emitted by a Thin Modulated Electron Beam

The theory of whistler wave interaction with a modulated electron beam of finite radius, injected parallel to the magnetic field in an unbounded space plasma is considered The study is done in the case of sheared whistlers interacting with the thin beam, when the parallel wave number is very small compared to the perpendicular one. The electromagnetic fields inside and outside the beam are dete...

Dopant Driven Electron Beam Lithography

An electron–positron beam–plasma instability

Using a new technique to generate cold electron beams, an electron-beam positron-plasma experiment was performed in a previously unexplored range of energies. An electron beam, formed from a thermalized room-temperature electron plasma, is transmitted through a positron plasma stored in a quadrupole Penning trap geometry. The transit-time instability, which is excited by the beam, was previousl...