J. MCCARRICK (LLNL)
Advanced accelerator-based radiographic diagnostics require multiple high-current electron beam pulses for temporal resolution. The use of 'kicked' beams or the failure of a tranport element on a prior pulse can result in the production a plasma plume from locations where the beam sweeps across the beam pipe, due to high thermal deposition by the beam. It is possible for this plasma to evolve to significant sizes (a substantial fraction of the pipe radius) over the course of several beam pulses. This asymmetric plume can then have deleterious effects on the transport of subsequent pulses due to dynamic image charge and and current effects, as well as ion emission into the beam, even if the beam does not pass directly through the plume. Some of these effects on beam deflection and emittance will be examined as a demonstration of three-dimensional numerical studies using highly customized desktop-based tools.
*This work performed under the auspices of the U.S. Department of Energy by LLNL under contract W-7405-ENG-48.
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