Diagnosing Shear-Flow-Stabilized Z-pinches on the Path to Breakeven

Zap Energy seeks to develop a scalable, compact fusion energy core that magnetically confines plasma in a shear-flow-stabilized Z-pinch configuration.  Two research devices, FuZE and FuZE-Q, serve as platforms to study fusion-grade plasmas as parameters are pushed toward those anticipated at breakeven.  As plasma current, magnetic field, density, temperature, and neutron yield rate scale in these research devices, the challenges associated with diagnosis change significantly.  We present recent diagnostic results and developments, as well as forward-looking strategies to characterize fusion gain as pinch diameter decreases and density and temperature increase.  Recent development efforts have focused on neutron anisotropy, dispersion interferometry, polarimetry, and Zeeman splitting.

Understanding of the plasmas present in Zap Energy devices has been significantly enhanced through public-private partnerships sponsored by ARPA-E.  These programs have brought significant instrumentation and expertise to bear, leading to important scientific results indicating that Zap research platforms produce neutron emission from thermalized deuterium plasmas with 1—3 keV temperatures and axial extent of tens of centimeters.