Physikalisch-Technische Bundesanstalt

A new nuclear demagnetization cryostat (MKA 3) is in operation for studies of condensed-matter phenomena at ultralow temperatures in high magnetic fields. The triple nuclear cooling stage, coupled to a powerful dilution refrigerator, is capable of maintaining lattice temperatures below 50 μK under a high magnetic field. For this purpose the system possesses a two-stage superconducting magnet; an upper 8.5-Tesla magnet for demagnetization and a lower magnet used for experimental fields up to 9 Tesla. The cryostat is protected from external sources of heat by vibration isolation and HF shielding.