Speaker
Description
To support the development of thin film SRF technology, STFC Daresbury Laboratory has commissioned a dedicated conduction-cooled SRF test facility for the rapid qualification of thin film coated cavities.
The facility is based on a Cryomech pulse tube cryocooler providing 2.7 W of cooling power at 4.2 K and supports RF measurements of both closed and split cavity geometries from 1.3 to 6 GHz. Since its initial design, the cryogenic facility and low level RF system have been fully commissioned. Cavity cooldown times of approximately 14 hours demonstrate the potential to test up to two cavities per week. Initial RF measurements using a bulk Nb 1.3 GHz single-cell TESLA cavity have demonstrated measurements of $Q_0(T)$ above 3.2 K, $Q_0(E_\rm{acc})$ measurements at fixed temperature and frequency shift measurements as a function of temperature through the superconducting transition. In addition, the first RF tests of thin film coated cavities have begun, providing valuable feedback for the optimisation of deposition parameters.
This talk will present the commissioning of the facility together with its first results obtained on bulk and thin film SRF cavities. Ultimately, the facility is intended to accelerate the development of high-performance Nb$_3$Sn-coated cavities by providing rapid RF qualification and feedback to guide coating optimisation prior to high-power liquid helium testing.