Researchers at Sandia National Laboratories have verified the stable, symmetric implosion of a beryllium liner, a critical step in the development of the Magnetized Liner Inertial Fusion (MagLIF) concept. In a series of non-fueled experiments on the Z machine, a pulsed-power driver delivering 18 million amps, a liner was accelerated to a velocity of 70 kilometers per second. X-ray diagnostics confirmed that the implosion maintained its cylindrical integrity throughout the 100-nanosecond compression, avoiding instabilities that could disrupt the process. These results, detailed in a *Physical Review Letters* paper, provide foundational experimental support for the hydrodynamic stability of the MagLIF target design, a necessary precursor to integrated experiments with fusion fuel. Source: Sandia (SNL)

The MagLIF approach is a form of magneto-inertial fusion that combines elements of both magnetic and inertial confinement. The concept involves three stages: first, an axial magnetic field is applied to a fuel-filled liner to inhibit thermal conduction losses. Second, a laser pre-heats the deuterium fuel to several hundred electron volts. Finally, the Z machine's powerful current generates an intense magnetic field that implodes the liner, compressing and heating the fuel to fusion conditions. The recent experiments focused solely on the third stage, demonstrating that the liner can be imploded symmetrically without pre-heating or an embedded magnetic field, which were intentionally omitted to isolate and study the implosion dynamics. Source: Sandia (SNL)

The MagLIF approach is a form of [magneto-inertial fusion](/analysis/tech-comparison) that combines elements of both magnetic and inertial confinement.

Achieving a symmetric implosion is paramount, as asymmetries can grow and prevent the target from reaching the required density and temperature for significant fusion yield. The experimental team, led by researcher Ryan McBride, used the Z machine's diagnostic capabilities to observe the liner's behavior during its rapid convergence. The data showed that the liner's inner surface remained smooth and cylindrical, matching computational models. This outcome suggests that the MagLIF design is robust against the magneto-Rayleigh-Taylor instability, a significant concern in liner implosion schemes. This validation of the implosion physics is a key milestone for the Sandia National Laboratories program. Source: Sandia (SNL)

With the successful demonstration of liner stability, the program's next phase will involve integrating the other core components of the MagLIF concept. Future experiments are planned to include the initial axial magnetic field to insulate the fuel and the laser pre-heating stage to establish the initial plasma conditions. These integrated tests will introduce additional physics and engineering complexities, including laser-plasma interactions and the effect of the magnetic field on energy transport. The ultimate goal is to achieve significant fusion energy gain. According to Sandia, a more advanced version of the Z machine could theoretically produce 100 to 1,000 times the energy it consumes, a projection that depends on the successful integration of all MagLIF subsystems. Source: Sandia (SNL)