Kinetic simulations of power flow in the Z accelerator
Abstract
The challenge for the Terawatt-class accelerators driving Z-pinch experiments, such as Sandia National Laboratories' Z machine, is to efficiently couple power from multiple storage banks into a single multi-mega amp (MA) transmission line. The physical processes that degrade efficiency are identified in the first-ever, multi-dimensional simulations of the Z machine. Kinetic models follow the range of physics occurring during a pulse, from vacuum pulse propagation to charged-particle emission and insulated flow to electrode plasma expansion. Simulations demonstrate that current is diverted from the load through a combination of standard and anomalous transport. Standard transport occurs in the adder region where the electrode current density is a few 104 -105 A/cm2 and current is diverted from the load via uninsulated charged-particle flows. In regions with >106 A/cm2, electrode surface plasmas develop velocity-shear instabilities and a Hall-field-related transport which scales with electron density. These results provide the physics basis for designing future pulsed-power systems.
Sandia National Labs is managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a subsidiary of Honeywell International, Inc., for the U.S Dept. of Energy's National Nuclear Security Administration under contract DE-NA0003525.- Publication:
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APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..DPPGI3006B