Charged-Particle Acceleration by Intense Electron Streams

Abstract

Accelerated protons and ions are observed when an intense relativistic electron stream is propagated through a gas-filled region. Several proton momentum peaks are observed for each stream pulse with a spread of \ensuremath{\le}10%, consistent with our resolution. Proton energies are independent of the filling gas for ${\mathrm{H}}_{2}$, ${\mathrm{N}}_{2}$, and air. Total ion fluxes are ${10}^{13}$ to ${10}^{15}$ particles/stream pulse. Nitrogen-ion tracks were too short to determine the charge state and hence the energy, but estimated upper limits suggest +4 or +5, consistent with the energy-to-change ratio observed for protons.