Very low friction rotator for use at low temperatures and high magnetic fields

We report the development of a sample rotating stage for use in a dilution refrigerator. The rotator makes use of bearings made from commercially available sapphire vee jewels and matching pivots that have extremely low coefficients of friction. This rotator allows continuous rotations through 360 degrees at low temperatures (30 mK) and high magnetic fields (20 T) with negligible sample heating. Rotations at rates less than 0.33 deg/s resulted in less than 50 mu W of dissipated power. Rotations at rates of 4.4 deg/s resulted in 383 mu W of heat dissipated. In addition, the rotator is capable of making rotations with a resolution as small as 0.020 degrees. (C) 1999 American Institute of Physics. [S0034-6748(99)03101-9].