Accelerator research, cavities are incerted into a cryounit. An accelerator uses electrons at high speeds to study smaller components of atoms called quarks. Cavities made from the element niobium are used to place positive and negative charges around electrons. A refrigeration container called a cryounit encases liquid helium around a pair of cavities keeping them superconductive. In superconductivity, certain substances lose resistance to the flow of an electric current. The use of superconductive niobium cavities allows the accelerator to provide a continuous beam of electrons to the experiments. Jefferson Lab's accelerator uses 338 cavities. Photographed at Jefferson Lab at Newport News, Virginia.