Observations of ion acceleration by a relativistic electron beam

Experimental evidence is presented for the collective acceleration of ions by a 350 keV, 50 kA, 100 ns electron beam. Accelerated ions are observed for vacuum injection, and at hydrogen fill-pressures below 50 mTorr. Measurements with different anode foils indicate that thicker foils reduce the number of ions accelerated. An applied magnetic field is found to increase the energy spread of the ions while leaving the total number accelerated unchanged. The total number of ions accelerated is about one trillion, with peak currents of 7 A.