Dielectric guide controlled collective ion acceleration

Relativistic electron beams with v/γ ≃ 1 have been propagated in a hard vacuum without external magnetic fields through cavities lined with dielectric materials⁽¹⁾. Charge neutralization was provided by ions removed from the surface of the dielectric liner by intense radiation bombardment. Protons were accelerated to energies 2 to 10 times the peak electron energy (70–100 keV). Ion energy increased with the cavity length. Ion velocity scaled directly as the injected current density. A model of the acceleration mechanism, correlating ion velocity with that of the electron beam front, will be presented. Subsequently, this work was scaled to higher energies ⁽²⁾.