Gabriel Shipley

  • Program Year: 2
  • Academic Institution: University of New Mexico
  • Field of Study: Magneto-Inertial Fusion
  • Academic Advisor: Mark Gilmore
  • Practicum(s):
    Los Alamos National Laboratory (2018)
  • Degree(s):
    B.A. Physics and Astrophysics, University of New Mexico, 2015

Summary of Research

Magnetized Liner Inertial Fusion (MagLIF) uses pulsed magnetic field to implode a metallic liner (cylindrical tube) to compress premagnetized, laser-preheated fusion fuel. To date, premagnetization has been provided by Helmholtz-like magnetic field coils positioned external to the liner. MagLIF experiments on Sandia's Z Machine utilizing these coils have successfully demonstrated thermonuclear conditions; however, eliminating the coils would improve x-ray diagnostic access and enhance current delivery to the target. Additionally, increasing the premagnetization strength above the maximum 30 Tesla that the coils can provide will help improve thermal insulation of the fuel.

Auto-magnetizing (AutoMag) liners are designed to generate up to 100 Tesla of axial magnetic field in the fuel for MagLIF without the need for external field coils. AutoMag liners are composed of discrete metallic helical conductors separated by electrically insulating material. Initially, helical current in the liner produces internal axial magnetic field during a long (100-200 nanoseconds) current prepulse provided by the pulsed power driver. After the cold fuel is magnetized, a rapidly rising current generates a strong electric field between the helices and breaks down the insulating material, reorienting current from helical to predominantly axial before the z-pinch liner implodes. My research primarily focuses on diagnosing the three stages of AutoMag (magnetization, breakdown, and implosion) in order to develop the AutoMag concept for use in MagLIF experiments.

Implosion stability is also important in MagLIF; performance (fusion yield) is degraded due to magnetically enhanced Rayleigh-Taylor instabilities (MRTI) that develop in the imploding liner which reduce liner convergence and limit attainable fuel temperatures and pressures. I am exploring the use of helical return current paths in MagLIF experiments to mitigate MRTI in liner implosions via a Solid Liner Dynamic Screw Pinch mechanism. This novel technique is designed to reduce MRTI growth by implementing a rotating drive magnetic field.

Publications

Papers:
G. A. Shipley, T. J. Awe, B. T. Hutsel, J. B. Greenly, C. A. Jennings, and S. A. Slutz. Implosion of auto-magnetizing helical liners on the Z facility. Invited Paper. Physics of Plasmas 26, 052705 (2019)

G. A. Shipley, T. J. Awe, B. T. Hutsel, S. A. Slutz, D. C. Lamppa, J. B. Greenly, and T. M. Hutchinson. Megagauss-level magnetic field production in cm-scale auto-magnetizing helical liners pulsed to 500 kA in 125 ns. Physics of Plasmas 25, 052703 (2018)

S. A. Slutz, C. A. Jennings, T. J. Awe, G. A. Shipley, B. T. Hutsel, and D. C. Lamppa. Auto-magnetizing liners for magnetized inertial fusion. Physics of Plasmas 24, 012704 (2017)


Presentations/Posters:
G. A. Shipley. Megagauss-level premagnetization field production in helically-wound auto-magnetizing liners for Magnetized Liner Inertial Fusion (MagLIF). Invited Talk. 60th Annual Meeting of the APS Division of Plasma Physics (2018)

G. A. Shipley, T. J. Awe, B. T. Hutsel, S. A. Slutz, J. B. Greenly, C. A. Jennings, D. C. Lamppa, and T. M. Hutchinson. Auto-magnetizing helical liners: megagauss-level premagnetization in pulsed power magneto-inertial fusion. Invited Talk. 9th Fundamental Science with Pulsed Power: Research Opportunities and User Meeting (2018)

G. A. Shipley, T. J. Awe, B. T. Hutsel, S. A. Slutz, J. B. Greenly, C. A. Jennings, D. C. Lamppa, and T. M. Hutchinson. Megagauss-level magnetic field and dielectric breakdown measured in auto-magnetizing liner experiments. Contributed Talk. 2018 IEEE International Conference on Plasma Science

G. A. Shipley, T. J. Awe, B. T. Hutsel, S. A. Slutz, J. B. Greenly, C. A. Jennings, D. C. Lamppa, and T. M. Hutchinson. Demonstration of megagauss-level premagnetization and cylindrical implosion symmetry in auto-magnetizing liner experiments for Magnetized Liner Inertial Fusion (MagLIF). Poster. 2018 DOE NNSA Stewardship Science Graduate Fellowship Annual Program Review

G. A. Shipley, S. A. Slutz, T. J. Awe, D. C. Lamppa, C. A. Jennings, and R. D. McBride. Auto-magnetizing liners for MagLIF experiments. Contributed Talk. 2016 IEEE International Conference on Plasma Science

G. Shipley, A. Kuskov, J. Romero, L. Lehr, S. Portillo. Radiation diagnostics and dosimetry modeling for characterization of plasma-beam interactions and x-ray production for a 500kV MILO. Poster. 2013 IEEE International Conference on Plasma Science

Awards

Dean's List, U of New Mexico: Fall 2011, Spring 2012, Fall 2012, Spring 2013, Fall 2013, Spring 2014.

Department Honors, U of New Mexico, Department of Physics and Astronomy: Magna Cum Laude in Physics and Astrophysics

Institution Honors, U of New Mexico: Summa Cum Laude

DOE NNSA Stewardship Science Graduate Fellowship, 2017-Present

Pass with Distinction awarded for Doctoral Comprehensive Exam, resulting in advancement to PhD Candidacy