Low Temperature Additive Manufacturing of Superconducting Radio Frequency Cavities

Superconducting radio frequency cavities are one of key technologies for the accelerator industry. They deliver extremely high beam acceleration with comparatively little power loss. They are, however, both challenging and expensive to manufacture. Current manufacturing methods damage the superconducting properties of the niobium by inducing contamination and loss of dimensional accuracy when they are machined, formed and electron beam welded. Atlas Technologies is proposing a novel seamless additive manufacturing method that eliminates electron beam welds, simplifies manufacturing and reduces cost, while potentially improving superconducting performance. Our method reduces the required amount of expensive niobium by approximately 92%. The bulk structural niobium is replaced with copper which enhances superconducting performance by improving heat transfer from the thin working layer of niobium to the exterior liquid Helium cooling bath. Our method is well suited for production manufacturing. It is versatile and can be used to tailor niobium and copper thickness in specific regions of the cavity. Phase I will investigate the superconducting properties of the niobium films produced with our method and will seek to refine the quality based on our findings. We will manufacture numerous niobium and copper coupons made with our method and characterize the superconducting performance. Adjustments to the process will be iteratively explored based on our findings. We will also seek to validate and refine enabling manufacturing tooling approaches which will be used to manufacture complete superconducting radio frequency cavities in Phase II. As more and more applications for accelerators are created the use of superconducting radio frequency cavities grows. They are increasingly used in practical applications such as medical, defense, biology and materials development. Remarkably, they even hold the promise of reducing nuclear waste via transmutation to safer byproducts. The global demand for superconducting radio frequency cavities is already significant. By reducing costs and improving performance the market will be quite substantial.