MiniRailguns for Fusion and HEDP

Magneto-inertial fusion and high-energy-density plasmas represent a promis­ing approach to the generation of fusion energy. In this area of fusion research, the ability to compress a magnetized target plasma, without the need to replace a solid driver, is crucial to further development. Mini-railgun plasma accelerators with low operating costs and high repetition rates are a possible approach to meeting this requirement. Therefore, this project will develop mini-railgun plasma accelerators that can produce high density plasma jets at high velocity. In Phase I, a series of prototype accelerators were designed, fabricated, and tested. When four mini-railguns were used in a symmetric plane geometry, the resulting convergence density was a factor of 20 larger than the density of a single jet. Small railguns (1 cm bore) achieved nearly 200 micrograms of plasma at 80 km/s with high energy density. In Phase II, the mini-railgun accelerators will be further developed, pushing their performance to above 1000 micrograms of plasma at greater than 50 km/s, while maintaining the high density. A fully three-dimensional jet merging and implosion test will be performed at modest energy using 20-26 mini-railguns. These tests will be used to validate hardware and techniques for a much larger planned experiment. Commercial Applications and other Benefits as described by the awardee: Mini-railgun plasma accelerators will be useful for commercial fusion power, refueling magneti­cally confined plasmas, high specific impulse thrusters for space propulsion, laboratory simulation of astrophysical jets, fast pulsed power switching, materials processing, and high-energy-density plasma research