Posen, S. Merio, M. Romanenko, A. Trenikhina, Y. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-TUPB048 English 678-680 TUPB048 niobium cavity SRF cryogenics accelerating-gradient Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-TUPB048 http://srf2015.vrws.de/papers/tupb048.pdf A substantial program has been initiated at FNAL for R&D on Nb3Sn coated cavities. Since early 2015, design, fabrication, and commissioning has been ongoing on a coating chamber, designed for deposition via vapor diffusion. The volume of the chamber will be large enough to accommodate not just R&D cavities, but full production-style cavities such as TeSLA 9-cells. In this contribution, we overview the development of the chamber and we introduce the R&D program planned for the coming years. We discuss research paths that may yield increased maximum fields and reduced residual resistances as well as new applications that could be explored with larger coated cavities.