Plasma Heating by Intense, Relativistic Electron Beams

Abstract

A partially ionized helium plasma (${n}_{e}=5\ifmmode\times\else\texttimes\fi{}{10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) was heated by an intense ($\frac{\ensuremath{\nu}}{\ensuremath{\gamma}}\ensuremath{\simeq}1$) relativistic electron beam (600 keV, 25-60 kA). Observations of the emitted line radiation and Thomson-scattered light indicate noncollisional electron heating rates consistent with electron-ion instability predictions, and total energy deposition consistent with electron-electron- instability saturation levels.