  Nb3Sn is a promising next-generation material for superconducting
radiofrequency cavities, with significant potential for both large scale and
compact accelerator applications. However, so far, Nb3Sn cavities have been
limited to cw accelerating fields <18 MV/m. In this paper, new results are
presented with significantly higher fields, as high as 24 MV/m in single cell
cavities. Results are also presented from the first ever Nb3Sn-coated 1.3 GHz
9-cell cavity, a full-scale demonstration on the cavity type used in production
for the European XFEL and LCLS-II. Results are presented together with heat
dissipation curves to emphasize the potential for industrial accelerator
applications using cryocooler-based cooling systems. The cavities studied have
an atypical shiny visual appearance, and microscopy studies of witness samples
reveal significantly reduced surface roughness and smaller film thickness
compared to typical Nb3Sn films for superconducting cavities. Possible
mechanisms for increased maximum field are discussed as well as implications
for physics of RF superconductivity in the low coherence length regime. Outlook
for continued development is presented.
