A NEW ULTRALOW TEMPERATURE CRYOSTAT IN HELSINKI

A new cascade nuclear demagnetization cryostat has been designed and c onstructed. Our aim has been to build a versatile, modular cryostat wi th a large experimental space providing an excellent platform for vari ous types of ultra-lon temperature measurements. A powerful dilution r efrigerator, combined with massive nuclear cooling stages, will enable us to reach the low temperatures necessary in studies of nuclear magn etic ordering. First experiments include nuclear magnetism in nh and s earch for superfluidity of He-3 in dilute mixtures. Details of the des ign and results of tile performance tests will be discussed.