Stability of fusion target concepts on Z.

Abstract

The key scientific issue for magnetically driven fusion concepts is the stability of the cylindrical liner surrounding the fuel. The liner is susceptible to the magnetoRayleigh-Taylor instability, which can disrupt the liner implosion and prevent it from successfully compressing and confining the fuel. We summarize an LDRD project to investigate the stability of aluminum and beryllium liner implosions on the Sandia Z pulsed power facility. Much of the work was conducted in the specific context of a new magnetized liner inertial fusion (MagLIF) concept, and continued modeling of that concept was supported by this project. However, the liner stability data is fundamental to magnetically driven systems, and the idea of magnetizing and preheating fuel applies to any inertial confinement fusion platform. We also demonstrated prototype 10 T axial magnetic field coils, which are needed both to test the MagLIF concept and the idea of stabilizing liner implosions using magnetic fields. 4 ACKNOWLEDGMENTSWe thank the many Z and Z-Beamlet operations and production teams for their excellent support of the liner stability experiments on Z that were undertaken as part of this project.We thank General Atomics for their support in developing and fabricating the liner targets fielded on the Z facility. Much of the work described here would not have been possible without the development of a beryllium machining capability in La Jolla, CA.We thank Ron Kaye (Manager, Org. 5445) for supporting the development of the Systems Integration and Test Facility in his laboratory space and for the use of Derek Lamppa and Marc Jobe to support the development of magnetic field coils.We thank Jim Puissant (Org. 1647) for supporting the magnetic field coil design and testing activities.We thank TJ Rogers (formerly Org. 1678) for designing the raised power-feed hardware for Z that is compatible with the magnetic field coils, and was tested during the "Washington" shots.We thank Dawn Flicker (Manager, Org. 1646) for supporting the collaboration between the ICF and Dynamic Materials program that enabled the "Union" experiments on Z. These experiments, while explicitly aimed at studying the equation of state of beryllium using cylindrical liners, are also relevant to ICF implosions and the techniques may ultimately benefit MagLIF.We thank the code support teams at LLNL for both LASNEX and HYDRA for helping us to advance the simulations conducted as part of this project. We also thank the support staff at numerous computing platforms at both SNL and LLNL who helped shepherd the simulations through to completion.