INVESTIGATING THE GENERATION AND TRANSPORT OF 10-12 MeV , 30-kA , mm-SIZE ELECTRON BEAMS WITH LINEAR INDUCTIVE VOLTAGE ADDERS seNj-+ jq-0 I 3 q ~

SABRE EXPERIMENTS We present the design, analysis, and results of the highbrightness electron beam experiments currently under investigation at Sandia National Laboratories. The anticipated beam parameters are the following: 8-12 MeV, 35-50 kA, 30-60 ns FWHM, and 0.5-mm rms beam radius. The accelerators utilized are SABRE a d HEMES III. Both are linear inductive voltage adders modified to higher impedance and fitted with magnetically immersed foilless electron diodes. In the strong 20-50 Tesla solenoidal magnetic field of the diode, nun-size electron beams are generated and propagated to a beam stop. The electron beam is field emitted from mmdiameter needle-shaped cathode electrode and is contained in a similar size envelope by the strong magnetic field. These extremely space charge dominated beams provide the opportunity to study beam dynamics and possible instabilities in a unique parameter space. The SABRE experiments are already completed and have produced 3CkA, 1.5-mm FWHM electron beams, while the HERMES-III experiments are on-going.