High-Gradient Insulators

High voltage systems operated in vacuum require insulating materials to maintain spacing between conductors held at different potentials. Traditional vacuum insulators consist of a single material, often machined with a 45deg angle to suppress surface flashover. However, insulating structures composed of alternating layers of dielectric and metal can also be built, and have been experimentally shown to have higher breakdown voltages than conventional insulators. These "high-gradient insulators" allow closer spacing of components in vacuum, and therefore; have application to a wide range of high-voltage vacuum systems where compact size is important. This paper describes ongoing simulations and experimental work on these structures, as well as the theoretical understanding driving this research