Dilution Refrigerator for Cryogenic Characterisation of RF Hardware

The National Physical Laboratory (NPL) is seeking engagement from suppliers who can provide "Dry" ("cryogen-free") pulse tube cooled dilution refrigerator system to be used for characterisation of quantum hardware including RF and quantum circuits with sample volume under vacuum. The system should include thermometry and associated wiring and readout electronics with provision to integrate additional temperature sensors in future for comprehensive diagnostics.

The purpose is to complement our existing measurement systems and add measurement capability, for characterisation of quantum and RF hardware with high throughput and faster cooldowns repeated typically every 2 weeks. The dilution refrigerator needs to be suitable for RF measurements of complex quantum circuits and hardware, meaning it must be equipped with 20+ coaxial lines with provision to further increase the number of coaxial lines in the future.

These lines must include high attenuation input lines suitable for use with sensitive quantum devices such as superconducting qubits and parametric amplifiers and low-loss output coaxial lines suitable for use with low-noise amplifiers, isolators and parametric amplifiers. Some of these coaxial lines must operate up to 40 GHz with provision to integrate even higher frequency RF cabling in the future.

There should be sufficient number of DC lines with sufficient reconfigurability to enable biasing of at least tens of RF multi-way switches, at least four low noise amplifiers and few dedicated high resistance and low resistance DC looms for devices under test with provision to integrate more DC looms in the future. The asset must enable the characterisation of quantum and cryogenic RF hardware based on the following: 1) Base temperature of less than or equal to 10 mK with access to PT2 and other intermediate stages for testing components at intermediate temperatures. 2) Mixing chamber plate area of at least 0.19m2 in horizontal space and vertical experimental sample space below the mixing chamber with a height of at least 400 mm accessible for custom experimental apparatus 3) We do NOT require a magnet.