Fabrication issues and technology development for HELEOS

Fabrication details, results of tests conducted, and areas for potential improvement in connection with the development of a hypervelocity electromagnetic launcher for equation of state (HELEOS) experiments are discussed. Common materials and fabrication technology are used in the manufacture of all components, and modular design allows for extending the length of the railgun as progress dictates. The launcher uses a `vee block´ geometry, which is designed to provide compressive preload, operate with a 300-MPa internal bore pressure, and easily accommodate interchangeable materials in the bore support structure and rail. Full-scale material testing of the railgun was performed, and a precision round-bore fabrication process was developed. Air-gage inspection is used to determine bore diameter and straightness