Potentially Smallest Fusion Device Using Improved Z-Pinch Fusion

ARPA-E-funded alternative z-pinch fusion which is being developed by Zap Energy.

Zap Energy is the most compact solution to Fusion Energy and does not use complex and costly magnetic coils. They surpassed ARPA-E Alpha Milestones in August 2018. Their reactor is consistently producing neutrons and they received $6.8 million ARPA-E OPEN funding.

* The new Z-pinch has the simplest geometry of any magnetic confinement configuration. It is a cylindrical plasma column.

The U.S. Department of Energy announced $98 million in funding for 40 new projects in 2018.

Talk Polywell has had discussions of this work.

Arxiv- Sustained neutron production from a sheared-flow stabilized Z-pinch (2018,2019)

The sheared-flow stabilized (SFS) Z-pinch has demonstrated long-lived plasmas with fusion-relevant parameters. This Letter presents the first experimental results demonstrating sustained, quasi-steady-state neutron production from the Fusion Z-pinch Experiment (FuZE), operated with a mixture of 20% deuterium/80% hydrogen by volume. Neutron emissions lasting approximately 5 µs are reproducibly observed with pinch currents of approximately 200 kA during an approximately 16 µs period of plasma quiescence. The average neutron yield is estimated to be (1.25±0.45)×100,000 neutrons/pulse and scales with the square of the deuterium concentration. Coincident with the neutron signal, plasma temperatures of 1 − 2 keV.

Employing the SFS Z-pinch concept, FuZE has achieved equilibrium-stabilized plasma with fusion-relevant parameters of 10^17 cm−3 number density, 1 − 2 keV temperature, 0.3 cm pinch radius, and long-lived quiescent periods of approximately 16 µs on a scale that facilitates diagnostic measurements. The demonstration of sustained neutron production lasting approximately 5 µs, thousands of the theoretical m = 1 mode growth time, the absence of m = 0 and m = 1 instabilities during neutron production, and the observation of neutron yield scaling indicate consistency with a thermonuclear fusion process. The measured neutron yields are approximately 100000 neutrons/pulse, consistent with theoretical expectations for the measured plasma parameters and within the statistical expectations of a steady-state line neutron source.

SOURCES- Lawrence Livermore National Labs, ARPA-E, Washington University, Arxiv
Written By Brian Wang. Nextbigfuture.com

Electrode Technology Development for the Sheared-Flow Stabilized Z-Pinch Fusion Reactor
Zap Energy Inc. | Seattle, WA | $6,767,334

Zap Energy will advance the fusion performance of the sheared-flow stabilized (SFS) Z-pinch fusion concept. SFS Z-pinch drives electrical current through a plasma to create magnetic fields that compress and heat the plasma toward fusion conditions. Under this project, the team will raise the electrical current, reduce physics risks relating to plasma stability and confinement, and develop the electrode technology and plasma-initiation techniques necessary to enable the next steps toward a functional SFS Z-pinch fusion power plant. This could provide nearly limitless, on-demand, emission-free energy with negligible fuel costs.