C-band accelerators have been of particular interest in recent years due to their ability to provide high gradients and transport high charge beams for applications such as colliders and medical technologies. New Advancements in high gradient technologies that can suppress the breakdown rate in a particular structure by using distributed coupling, cryogenic cooling, and copper alloys. Previous work has shown each of these separately to significantly improve the maximum gradient. In this work, for the first time, we will combine all three methods in an ultra-high gradient structure and benchmark the difference between Cu and CuAg. The exact same structures were previously tested at room temperature and showed gradients in excess of 200 MeV/m and a 20% improvement in the CuAg version over its pure Cu counterpart [1]. These structures are now tested at 77K simultaneously. They were found to perform similarly due to the presence of significant beam loading. Taking beam loading into account, a maximum achievable gradient of 200 MeV/m achieved for a 1 µs pulse at an input power of 5 MW into each cavity with a breakdown rate of 1e-1 breakdown/pulse/m.

Niobium cavities are key elements in superconducting radiofrequency (SRF) accelerators. Despite increasing worldwide demand, global commercial production capacity is limited to a small number of vendors with virtually no US-based turn-key suppliers. As SRF technology expands across scientific research, industry, and technology sectors, the demand for their production is expected to rise even more in the coming years. Due to the limited supply base and very long delivery times, the US accelerator community is seeking to promote new vendors to enter SRF business capable of rapid iteration of low-volume/high mix R&D cavities. RadiaBeam has been involved in developing niobium fabrication capabilities for several years now, with the objective of understanding the technological challenges and commercial opportunities. In this paper, we present the progress in fabrication process of a single 1.3 GHz TESLA-style niobium cavity at RadiaBeam. This process involves the deep drawing of half cells, machining of weld joints, chemical cleaning, and electron beam welding capabilities.