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
