Researchers at the DOE's Argonne National Laboratory have developed new state-of-the-art techniques that will lead to significant improvements in the performance of superconducting niobium cavities. Argonne's superconducting spoke cavities can operate at lower temperatures and at higher magnetic fields than previous designs, translating into a potential savings in the cost of a heavy-ion linear accelerator, such as that required for the proposed Facility for Rare Isotope Beams (FRIB).