Cryogen-Free Dilution Refrigerator System for Quantum and RF Hardware Testing

The National Physical Laboratory (NPL) seeks a supplier for a dry, pulse tube cooled dilution refrigerator system designed for characterizing quantum hardware and RF circuits. The system must achieve a base temperature of ≤10 mK with access to intermediate temperature stages (PT2 and above) for component testing. The mixing chamber must provide at least 0.19 m² of horizontal plate area and 400 mm of vertical experimental space below for custom apparatus. The refrigerator must be equipped with 20+ coaxial transmission lines with provision for future expansion, including high-attenuation input lines for sensitive quantum devices (superconducting qubits, parametric amplifiers) and low-loss output lines for low-noise amplifiers and isolators. Multiple coaxial lines must operate up to 40 GHz with capability to support higher frequencies. The system must include adequate reconfigurable DC lines to bias RF multi-way switches, at least four low-noise amplifiers, and multiple device biasing looms with provision for future expansion. Full thermometry and readout electronics must be provided with the ability to integrate additional temperature sensors. The system should enable high-throughput testing with rapid cooldown cycles occurring approximately every 2 weeks. No magnet is required.