DEVELOPMENT OF A PIEZOMAGNETOMETER

WE PROPOSE TO DEVELOP A MAGNETOMETER THAT USES MAGNETOSTRICTIVE AND PIEZOELECTRIC ELEMENTS TO ATTAIN A SENSITIVITY APPROACHING 1 PICOTESLA PER ROOT HERTZ IN A SMALL, LOW COST, LOW POWER INSTRUMENT OPERATING AT AMBIENT TEMPERATURE. SUCH SENSITIVITY NOW REQUIRES EITHER A COSTLY, HIGH-POWER MAGNETOMETER (E.G., A FLUXGATE) OR A SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE (SQUID) THAT NEEDS EXPENSIVE AND CUMBERSOME CRYOGENICS TO OPERATE. OUR CONCEPT FOR A PIEZOMAGNETOMETER (PM) USES AN ELECTROMETER CIRCUIT TO MEASURE POLARIZATION CHANGES INDUCED ON THE SURFACE OF A PIEZOELECTRIC CRYSTAL BOUND BY A MAGNETOSTRICTIVE FILM. IN PHASE I, WE TEST CANDIDATE PIEZOELECTRIC AND MAGNETOSTRICTIVE MATERIALS TO SELECT THOSE GIVING HIGH TEMPERATURE, DEVELOP A HIGH GAIN TRANSDUCER USING THE SELECTED MATERIALS, AND USE THE TRANSDUCER TOGETHER WITH A COMMERCIALLY AVAILABLE ELECTROMETER TO DEMONSTRATE FEASIBILITY OF THE CONCEPT AND TO CALIBRATE ITS PERFORMANCE. IT LEADS TO PHASE II DEVELOPMENT OF A SMALL, LOW POWER, INTEGRATED PROTOTYPE PM SUITABLE FOR FIELD DEPLOYMENT. ANTICIPATED BENEFITS/POTENTAILCOMMERCIAL APPLICATIONS OF THE RESEARCH OR DEVELOPMENT. THE PIEZOMAGNETOMETER CAN PROVIDE MORE SENSITIVITY THAN PRESENT ROOM TEMPERATURE MAGNETOMETERS (E.G., ALKALI VAPOR OR FLUXGATE SENSORS) AND MORE CONVENIENCE THAN CRYOGENIC (SQUID) SENSORS. THESE SMALL, LOW POWER UNITS CANBE SCATTERED IN A COMBAT ZONE TO DETECT MOVEMENTS OF VEHICLES AND COMBATANTS. THEY CAN ALSO AUGMENT CAPABILITIES IN ANTISUBMARINE WARFARE,MINE DETECTION, AND MINE FUSING. COMMERCIAL USES INCLUDE MINERAL ANDOIL EXPLORATION, LOCATING BURIED CABLES AND PIPELINES, NONDESTRUCTIVETESTING, AS WELL AS BIOMAGNETIC AND MATERIALS RESEARCH.