Large radius Z-discharge transport channel studies for applications on saturn

Summary form only given, as follows. High-current relativistic electron beams (e-beams) produced on the Saturn pulsed power accelerator at Sandia National Laboratory (SNL) can be used to generate high dose bremsstrahlung radiation. Typically, multiple concentric ring diodes on Saturn produce currents of approximately 10 MA at voltages of about 1.7 MV. For some applications, radial convergence of the outer rings to smaller radius is required; one technique used to converge the beams is Z-discharge transport (ZDT). To study the beam characteristics and transport efficiencies in ZDT channels at various pressures, 2D fluid/PIC hybrid simulations and bench-top experiments are performed in which In simulations, discharge currents through a plasma were approximated by an applied B/sub /spl theta//-field, thereby promoting radial convergence onto a target-plane at a distance downstream (/spl sim/1/4-betatron wavelength, see figure). Self-fields and collisions were modeled in the channel self-consistently using a tenuous medium model. Bench-top experiments are under way to study the possible discharge current and background electron density profiles that could be achieved.