Simulation and Validation of Dynamic Screw Pinch-Driven Liner Implosions in FLASH

Dynamic screw-pinch (DSP) geometries have been shown to effectively mitigate magneto Raleigh- Taylor instability growth in magnetized liner inertial fusion (MagLIF) experiments [1]. Simulations suggest that designs using a DSP in addition to static magnetization, or in tandem with a composite liner, could reach significantly higher fusion yields on Z when compared to uniform premagnetization alone [2]. Of particular importance for this platform is understanding the in-flight axial magnetic diffusion through the liner, which is necessary to properly insulate the fuel against conduction losses.

In order to study this platform, the capability to simulate the circuit-coupled axial-field boundary condition generated by a DSP return-can has been developed in the FLASH radiation hydrodynamics code. Comparison of FLASH simulations with published 3D KRAKEN simulations, the potential for high-gain 60-MA geometries, and validation of magnetic diffusion rates with experiments on the 1-MA Michigan Linear Transformer Driver facility will be discussed.

[1] Paul C. Campbell, et. al; Liner implosion experiments driven by a dynamic screw pinch. Phys. Plasmas 1 August 2021; 28 (8): 082707.

[2] G. A. Shipley, et. al; Integrated simulations of premagnetized and self-magnetizing dynamic screw pinch-driven MagLIF. Phys. Plasmas 1 May 2025; 32 (5): 052708.