MARAUDER is, or was, a United States Government research project. It is an acronym of Magnetically Accelerated Ring to Achieve Ultra-high Directed Energy and Radiation. It was first reported on August 1, 1993.
The objective appears to be the firing of 1 meter diameter toroids of magnetically contained plasma. The toroids behave nothing like spheromak fusion reactors, as the toroidal shape results from self-confinement behavior as the toroid interacts with the atmosphere as it moves at high speed. As of 1993[update] the project appeared to be in the early experimental stages. The weapon was able to produce doughnut shaped rings of plasma and balls of lightning that exploded with devastating effects when hitting its target. The project's initial success led to it becoming classified and no more details of how it developed after 1993 are available.