Mechanical Engineering Center’s Masterpiece: Four Units of 3-Cell Superconducting Accelerating Cavities

(English translation 2024-05-20)

This is a 3-cell superconducting accelerating cavity manufactured at the Cavity Fabrication Facility (CFF), jointly operated with the Accelerator Laboratory, Center for Applied Superconducting Accelerators Center (CASA). Previously, we used fine-grained materials with niobium crystals, but now we are utilizing materials sliced from niobium ingots (known as large-grain materials due to their larger crystals). This approach allows us to simplify the complex processing steps involved in material fabrication, potentially leading to cost reduction. There were unexpected issues such as ongoing breakdowns and repairs of the electron beam welding machines, but we were able to complete all four units by the end of the fiscal year 2020. Currently, we are conducting vertical measurements for performance evaluation.