Gauss Fusion preprint outlines plasma-equilibrium design basis for proposed 1 GWe stellarator

A Gauss Fusion-led research team has posted a new arXiv preprint laying out the plasma-equilibrium design basis for a proposed 1 gigawatt-electric stellarator power plant. The 40-page manuscript, posted July 10 as arXiv:2607.09346v1, is titled “The fixed boundary plasma equilibrium basis for a one Gigawatt electric stellarator power plant.”

The paper is a simulation and design study, not an experimental reactor result. It does not describe a built or operating plant, and it is not evidence that a device has generated 3 gigawatts of fusion power. The PDF appears formatted for Plasma Physics and Controlled Fusion, but arXiv does not indicate peer-review status. The corresponding author is Samuel Lazerson of Gauss Fusion GmbH.

In the abstract, the authors say the study presents a fixed-boundary stellarator equilibrium “capable of producing 3 GW of fusion power (1 GW-electric)” as the design basis for Gauss Fusion’s GIGA power-plant concept. Gauss Fusion publicly describes GIGA on its corporate website as its stellarator power-plant concept. The paper is by Lazerson and co-authors, including the Gauss Fusion Team, with affiliations listed as Gauss Fusion GmbH, Karlsruhe Institute of Technology, the Technical University of Denmark, Research Instruments GmbH, and VTT Technical Research Centre of Finland.

The study reports several design targets for the proposed plasma configuration. Among them are alpha power confinement greater than 85%, neoclassical effective ripple below 0.01, bootstrap current below 50 kiloamps, reduced turbulent heat fluxes, and a fixed plasma volume of 1,500 cubic meters. The manuscript says the final equilibrium met the required targets after more detailed modeling of stability, fast-ion confinement and transport.

According to the paper, the team started from a modified equilibrium based on Wendelstein 7-X, or W7-X, and then optimized it using the stellarator codes VMEC and STELLOPT. The authors say they modified VMEC so plasma volume stayed fixed during optimization, and modified STELLOPT to add new targets for bootstrap current, radial electric field and a fixed on-axis magnetic field.

A stellarator is a magnetic-confinement fusion device designed for steady-state operation. It is often discussed as an alternative to tokamaks because it aims to avoid pulsed operation and some plasma transients. W7-X, operated in Greifswald, Germany, is the world’s largest advanced stellarator experiment and a major reference point for the field, making a W7-X-derived starting point notable for plant design work.

At the same time, a fixed-boundary equilibrium is an early design step focused on the target plasma shape and confinement properties. It does not settle later engineering problems such as whether the coils can be manufactured, how superconducting magnets would be built, how tritium breeding and heat exhaust would work, what materials would survive in service, or how a plant would meet licensing requirements.

That makes the new paper a significant design-basis milestone rather than a reactor milestone. It sketches the plasma physics foundation for a proposed 1 gigawatt-electric stellarator plant, but major engineering, validation and review steps would still lie ahead before any such concept could be tested in hardware.