Production of a high brightness beam from a large surface source

An experiment was set up on a 500-kV test stand to study the beam optics of an extraction diode using a 10-cm diameter alumino-silicate source. The beam was also sent through an aperture to reduce aberrations, thus enhancing its brightness. In comparing the experimental results with WARP-3D computer simulations, we found excellent agreement in the emittance diagrams and in the beam current rise-time. By benchmarking the computer code, we now have the capability to perform detail optical designs and to create the proper voltage waveform for producing a current pulse with a fast rise-time. A fast rise-time pulse is desirable because many potential near-term HIF experiments will require short beam pulses which have a fast rise-time.