Sustained neutron production from a sheared-flow stabilized Z-pinch

TL;DR

This paper reports the first experimental observation of sustained, quasi-steady-state neutron production from a sheared-flow stabilized Z-pinch, demonstrating fusion-relevant plasma conditions and neutron yields.

Contribution

It provides the first experimental evidence of sustained neutron production in a sheared-flow stabilized Z-pinch with specific plasma parameters and neutron yield scaling.

Findings

Neutron emissions lasting about 5 microseconds observed.

Neutron yield estimated at approximately 1.25×10^5 neutrons per pulse.

Neutron production scales with the square of deuterium concentration.

Abstract

The sheared-flow stabilized $Z$-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 $5~\mu$s are reproducibly observed with pinch currents of approximately $200$ kA during an approximately $16~\mu$s period of plasma quiescence. The average neutron yield is estimated to be $\left ( 1.25\pm 0.45 \right )\times 10^{5}$ neutrons/pulse and scales with the square of the deuterium concentration. Coincident with the neutron signal, plasma temperatures of $1-2$ keV, and densities of approximately $10^{17}$ cm$^{-3}$ with $0.3$ cm pinch radii are measured with fully-integrated diagnostics.