Detailed Spectra of High-Power Broadband Microwave Emission from Intense Electron-Beam-Plasma Interactions

Abstract

For a relativistic electron beam penetrating an unmagnetized plasma, a change is seen in the emission spectrum from $\omega \sim {\omega }_p$, $2{\omega }_p$ line emission to continuous $\omega \gg {\omega }_p$ emission, as $\frac{n_b}{n_p}\to 1$. High-power (of order megawatts per gigahertz) broadband radiation up to ∼100 GHz suggests collective Compton-boosting mechanisms in a new regime of superstrong turbulence. Highly directional emission and magnetic field dependence agree with this interpretation.