Investigation of ion acceleration in vacuum using a linear electron beam

Acceleration of ions by intense relativistic electron beams in a vacuum has been studied using the injector of the Maryland ERA. Effects of floating electrodes and an impressed axial magnetic field were investigated. Maximum proton energies above 16 MeV and proton beam currents of 12 kA were obtained. An impressed axial magnetic field of 1.8 kilogauss resulted in focused proton beams less than 1 cm in diameter.