  Superconducting radio-frequency (SRF) accelerating cavities are a promising
technology for compact, high-power, MeV-scale accelerators, providing
continuous beam operation for a wide range of potential applications in
industry, medicine, national security, and science. However, SRF cavities have
traditionally been cooled using complex and expensive cryogenic infrastructure,
which has been a significant obstacle in employing this powerful technology in
small-scale systems. With the recent progress on high-performance
Nb$_3$Sn-coated SRF cavities and the introduction of cryocoolers, which can
provide turn-key style conduction cooling below 4.2 K, this barrier can now be
overcome. At Cornell University, we have developed a prototype setup that
utilizes a commercial cryocooler to provide the necessary cooling for operation
of a 2.6 GHz Nb$_3$Sn-coated SRF cavity. We have now demonstrated first stable
operation in continuous mode at accelerating fields up to 10 MV/m with a
quality factor of Q$_0$ = 4x10$^9$, thereby achieving an important milestone in
making turn-key SRF a reality.
