Equilibrium and Stability Properties of Low Aspect Ratio Mirror Systems: from Neutron Source Design to the Parker Spiral

POSTER

Abstract

Equilibrium reconstructions of rotating magnetospheres in the lab are computed using a user-friendly extended Grad-Shafranov solver written in Python and various magnetic and kinetic measurements. The stability of these equilibria are investigated using the NIMROD code with two goals: understand the onset of the classic ``wobble" in the heliospheric current sheet and demonstrating proof-of-principle for a laboratory source of high-$\beta$ turbulence. Using the same extended Grad-Shafranov solver, equilibria for an axisymmetric, non-paraxial magnetic mirror are used as a design foundation for a high-field magnetic mirror neutron source. These equilibria are numerically shown to be stable to the m=1 flute instability, with higher modes likely stabilized by FLR effects; this provides stability to gross MHD modes in an axisymmetric configuration. Numerical results of RF heating and neutral beam injection (NBI) from the GENRAY/CQL3D code suite show neutron fluxes promising for medical radioisotope production as well as materials testing. Synergistic effects between NBI and high-harmonic fast wave heating show large increases in neutron yield for a modest increase in RF power.

Authors

  • Ethan Peterson

    Univ of Wisconsin, Madison

  • J. K. Anderson

    Univ of Wisconsin, Madison, UW-Madison

  • Michael Clark

    University of Wisconsin - Madison, Univ of Wisconsin, Madison

  • Jan Egedal

    Univ of Wisconsin-Madison, University of Wisconsin - Madison, UWisc, Univ of Wisconsin, Madison, University of Wisconsin-Madison, UW-Madison

  • Douglass Endrizzi

    Univ of Wisconsin, Madison, University of Wisconsin--Madison

  • Ken Flanagan

    University of Wisconsin - Madison, University of Wisconsin-Madison, Univ of Wisconsin, Madison

  • Robert Harvey

    CompX

  • Jacob Lynn

    Univ of Wisconsin, Madison

  • Jason Milhone

    University of Wisconsin - Madison, Univ of Wisconsin, Madison, University of Wisconsin-Madison

  • John Wallace

    Univ of Wisconsin, Madison

  • Roger Waleffe

    Univ of Wisconsin-Madison, Univ of Wisconsin, Madison

  • Vladimir Mirnov

    Univ of Wisconsin, Madison

  • Cary Forest

    University of Wisconsin, Madison, University of Wisconsin - Madison, Univ of Wisconsin-Madison, Univ of Wisconsin, Madison, University of Wisconsin--Madison