A cryomagnetic system achieving 17T and <3mK

The design and performance of a cryomagnetic facility capable of achieving a temperature of 3mK in a magnetic field of 17T is presented. Using adiabatic nuclear demagnetisation of a copper stage, a3He melting curve thermometer may be cooled to a temperature below 914μK, the spin ordering temperature of the solid3He. The lower end of a silver rod coupled to this stage and extending into a 17T magnetic field cools to below 3mK, where the nuclear heat capacity of the silver is rising. The careful design of the vibration isolation of the cryostat reduces the heat leak in full field to below 2nW. This cryostat is currently being used for quantum oscillation studies of the heaviest quasiparticles associated with heavy fermion systems.