Superfluidity and quantized vortex studies under rotation up to 4 Hz at mK and 1 Hz at sub-mK temperatures

Two new high-speed rotating cryostats at the ISSP, University of Tokyo, capable of operating at mK temperatures, are currently employed for studies of superfluidity and quantized vortex states in He-4 and He-3. A stable high-Q torsional oscillator is used for the study of superfluidity in low-density He-4 films adsorbed on 3-D connected porous substrates. At T-c, the critical phenomena of 3-D Bose superfluids is seen. Under rotation a new type of vortex state is observed. High-resolution NMR studies of superfluid He-3, contained in capillary arrays of two different diameters, are made as a function of rotational speed. In these experiments, single vortex intrusion events as well as texural modification under rotation are clearly resolved. (C) 2003 Elsevier Science B.V. All rights reserved.