The design and analysis of a high brightness electron beam experiment under construction at Sandia National Laboratory is presented. The beam energy is 12 MeV, the current 35–40 kA, the rms radius 0.5 mm, and the pulse duration FWHM 40 ns. The accelerator is SABRE [J. Corley, J. A. Alexander, P. J. Pankuch, C. E. Heath, D. L. Johnson, J. J. Ramirez, and G. J. Denison, inProceedingsoftheEighthInternationalIEEEPulsedPowerConference, San Diego, California, 1991 (IEEE, New York, 1991), p. 920], a pulsed inductive voltage adder, and the electron source is a magnetically immersed foilless diode. This experiment has as its goal to stretch the technology to the edge and produce the highest possible electron current in a submillimiter radius beam. ©1996 American Institute of Physics.