HoBiCaT (Horizontal bi-cavity testing facility) has been designed for testing two
multicell superconducting cavities simultaneously under accelerator-like conditions: cavities can be fully equipped with input power couplers, pickup probes, HOM-notch pickups, tuners, and magnetic shielding. The vacuum vessel is 3.8 m long and 1.2 m in diameter with access doors at both ends. Ancillary devices or feedthroughs can be attached to the cryostat at over 30 KF, ISO-K, and CF flanges of different sizes. The inner wall of the vessel is clad with cryoperm optimized for room temperature. A cylindrical copper sheet of 1.1 m diameter is mounted inside the vessel, serving as an 80 K intercept. It is cooled with liquid nitrogen at 40 l/h. This copper layer is wrapped in superinsulation foil. Inside the cryostat, a 3.5 m long, horizontally mounted, hollow, extruded aluminum profile with a flat top and two longitudinal grooves serves as mechanical support for a cavity carriage that slides along the grooves. The cavities inside their helium tanks are mounted on this carriage. The profile’s hollow interior is filled with liquid helium at atmospheric pressure.
Typical operation temperature is 1.8 Kelvin and can go as low as 1.5 Kelvin. Static losses at these temperatures are 8-12 Watt.