Accelerator Development in Argonne’s Physics Division specializes in the design, fabrication and commissioning of high-intensity ion and electron accelerator systems. The first use of superconducting niobium radio-frequency cavities for ion acceleration was in 1977 at Argonne’s Tandem Linac Accelerator System. Since then, the Accelerator Development Group has been a world leader in the field of radio-frequency superconductivity and its applications to accelerators.