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 11993.
The objective appears to be the firing of 1 meter diameter toroids of magnetically contained plasma. The toroids behave in a similar manner to spheromak plasma reactors. the project appeared to be in the early experimental stages.