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Title: Three-dimensional magnetohydrodynamic modeling of auto-magnetizing liner implosions on the Z accelerator

Journal Article · · Physics of Plasmas
DOI: https://doi.org/10.1063/5.0162359 · OSTI ID:2311415

Auto-magnetizing (AutoMag) liners are cylindrical tubes that employ helical current flow to produce strong internal axial magnetic fields prior to radial implosion on ~100 ns timescales. AutoMag liners have demonstrated strong uncompressed axial magnetic field production (>100 T) and remarkable implosion uniformity during experiments on the 20 MA Z accelerator. However, both axial field production and implosion morphology require further optimization to support the use of AutoMag targets in magnetized liner inertial fusion (MagLIF) experiments. Data from experiments studying the initiation and evolution of dielectric flashover in AutoMag targets on the Mykonos accelerator have enabled the advancement of magnetohydrodynamic (MHD) modeling protocols used to simulate AutoMag liner implosions. Implementing these protocols using ALEGRA has improved the comparison of simulations to radiographic data. Specifically, both the liner in-flight aspect ratio and the observed width of the encapsulant-filled helical gaps during implosion in ALEGRA simulations agree more closely with radiography data compared to previous GORGON simulations. Although simulations fail to precisely reproduce the measured internal axial magnetic field production, improved agreement with radiography data inspired the evaluation of potential design improvements with newly developed modeling protocols. Three-dimensional MHD simulation studies focused on improving AutoMag target designs, specifically seeking to optimize the axial magnetic field production and enhance the cylindrical implosion uniformity for MagLIF. Importantly, by eliminating the driver current prepulse and reducing the initial inter-helix gap widths in AutoMag liners, simulations indicate that the optimal 30–50 T range of precompressed axial magnetic field for MagLIF on Z can be accomplished concurrently with improved cylindrical implosion uniformity.

Research Organization:
Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program
Grant/Contract Number:
NA0003525; NA0003864
OSTI ID:
2311415
Report Number(s):
SAND--2023-11395J
Journal Information:
Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 30; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (18)

Pulsed-power-driven cylindrical liner implosions of laser preheated fuel magnetized with an axial field journal May 2010
Modified helix-like instability structure on imploding z-pinch liners that are pre-imposed with a uniform axial magnetic field journal May 2014
Pulsed-coil magnet systems for applying uniform 10–30 T fields to centimeter-scale targets on Sandia's Z facility journal December 2014
Auto-magnetizing liners for magnetized inertial fusion journal January 2017
Design and testing of a magnetically driven implosion peak current diagnostic journal April 2018
Megagauss-level magnetic field production in cm-scale auto-magnetizing helical liners pulsed to 500 kA in 125 ns journal May 2018
Implosion of auto-magnetizing helical liners on the Z facility journal May 2019
Design of dynamic screw pinch experiments for magnetized liner inertial fusion journal October 2019
On the initiation and evolution of dielectric breakdown in auto-magnetizing liner experiments journal March 2022
Data-driven assessment of magnetic charged particle confinement parameter scaling in magnetized liner inertial fusion experiments on Z journal May 2023
X-ray generation mechanisms in three-dimensional simulations of wire array Z-pinches journal November 2004
Spatially resolved measurements of load current delivery on a 14 MA, 100 ns pulsed power experiment using a line-imaging velocity interferometer journal July 2023
Experimental Demonstration of Fusion-Relevant Conditions in Magnetized Liner Inertial Fusion journal October 2014
Understanding Fuel Magnetization and Mix Using Secondary Nuclear Reactions in Magneto-Inertial Fusion journal October 2014
Three-dimensional electromagnetic model of the pulsed-power Z -pinch accelerator journal January 2010
High-Current Linear Transformer Driver Development at Sandia National Laboratories journal April 2010
Assessing Stagnation Conditions and Identifying Trends in Magnetized Liner Inertial Fusion journal May 2019
The Refurbished Z Facility: Capabilities and Recent Experiments journal June 2009