Macron Formed Liner as a Practical Method for Enabling Magneto-Inertial Fusion

Abstract

To take advantage of the smaller scale, higher density regime of MIF an efficient and repeatable method for achieving the compressional heating required to reach fusion gain conditions is needed. The macro-particle (macron) formed liner compression of the field reversed configuration (FRC) provides such a method. The approach to be described employs an assemblage of small, gram scale, macrons to form a more massive liner that both radially and axially compresses and heats the FRC plasmoid to fusion conditions. The large liner energy (several MJ) required to compress the FRC is carried in the kinetic energy of the full array of macrons. The much smaller energy required for each individual macron is obtained by accelerating the macron to ~3 km/s which can be accomplished remotely using conventional inductive techniques. 3D numerical calculations demonstrate that macron convergence can form a coherent liner provided minimum velocity and timing accuracy is met. Experimental results have demonstrated that a cylindrical or spherical macron can be accelerated to velocity within 2 m/s and timing less than 1 microsecond. Initial testing of a 6-stage launcher yielded 280 m/s at a final coupling efficiency of greater than 40%.