We have modified the design of our commercial “Electrocurtain” electron-beam accelerators to provide for pulsed, medium current-density beams(10–30 mA/cm2)with a total output beam-area in the range of1000–1500 cm2. Two different approaches to the design of such systems are presented. In the first approach, a cylindrically symmetric geometry is employed, with the cathode extending along the symmetry axis (typically 1-m long). Beam expansion to the desired output area is dominated by the electric fields in the coaxial accelerating gap. For the second approach, several short cathodes span the short dimension of the output window and are evenly spaced along the long dimension of the window. Beam expansion is achieved in a field-free region. In both cases, the beam current is provided by cylindrically divergent Pierce-type diodes fitted with barium-dispenser cathodes. This design allows for grid control of the output current independent of the main accelerating voltage. Computer simulations of the beam flow will be discussed.