PIEZOELECTRICALLY DRIVEN MICROPOSITIONERS FOR ROTATION AT NORMAL AND CRYOGENIC TEMPERATURE IN HIGH MAGNETIC FIELDS.

CERTAIN INSTRUMENTS USED TO MEASURE PROPERTIES OF THE MAGNETIC FIELDS OF THE SUPERCONDUCTING SUPER COLLIDER (SSC) REQUIRE MECHANICAL ROTATION OF SENSOR ELEMENTS WITH FINE ANGULAR RESOLUTION AND CONTROLLED SPEEDS. ROTARY MICROPOSITIONERS CAPABLE OF OPERATION IN HIGH MAGNETIC FIELDS AND PROVIDING THE SPEEDS AND RESOLUTION REQUIRED FOR THE SENSORS HAVE BEEN DEVELOPED USING MICRO PULSE SYSTEMS (MPS) PROPRIETARY PIEZOELECTRIC DRIVE TECHNOLOGY. THESE MICROPOSITIONERS ACHIEVE DESIRED PERFORMANCE AT ROOM TEMPERATURE, BUT EMPLOY MATERIALS AND DESIGN CONFIGURATIONS THAT ARE NOT EXPECTED TO BE SATISFACTORY AT TEMPERATURE AS LOW AS 4K. TESTS OF A DIFFERENT DESIGN OF ROTARY ACTUATOR USING THE MPS PIEZOELECTRIC DRIVE SHOW THAT OPERATION AT 80KIS FEASIBLE. IN PHASE I INFORMATION ON SOME SIGNIFICANT PROPERTIES AT CRYOGENIC TEMPERATURES OF CANDIDATE MATERIALS FOR CONSTRUCTION OF THE MICROPOSITIONER WILL BE SOUGHT IN PUBLISHED DATA AND BY EXPERIMENTAL MEASUREMENT WHEN DATA IS NOT AVAILABLE. ALTERNATE CONFIGURATIONS AND ASSEMBLY METHODS TO ADAPT THE DESIGN FOR SATISFACTORY PERFORMANCE OVER THE TEMPERATURE RANGE WILL BE STUDIED, AND SOME DESIGNSWILL BE BUILT AND TESTED FOR SPEED, TORQUE AND RESOLUTION. INFORMATION ON THE VARIATION OF ELECTRICAL INPUT REQUIREMENTS OVER THE TEMPERATURE RANGE WILL BE OBTAINED.