ELECTROMAGNETIC GAGE TECHNIQUES FOR HEST MEASURMENTS

DATA ON THE RESPONSE OF MATERIALS AND STRUCTURES TO NUCLEAR WEAPONS IS CRITICAL TO THE IMPROVED DESIGN OF WEAPONS AND DEFENSE SYSTEMS. MUCH OF THIS DATA IS OBTAINED IN HIGH EXPLOSIVE SIMULATION (HES) TESTS. FOR BOTH HES AND NUCLEAR TESTS, INSTRUMENTATION TO OBTAIN THE REQUISITE DATA MUST BE ABLE TO FUNCTION PROPERLY IN THE HARSH ENVIRONMENT OF THE TESTS. INSTRUMENTATION TRADITIONALLY EMPLOYED IN SUCH TESTS UTILIZES GAGES GENERALLY DEPENDENT UPON SOLID-STATE PIEZOELECTRIC OR PIEZORESISTIVE PHENOMENON. AS BOTH PIEZORESISTIVE AND PIEZOELECTRIC CALIBRATION FACTORS CAN BE ADVERSELY AFFECTED BY THE HIGH STRESS AND/OR RADIATION LEVELS IN THE TEST ENVIRONMENT, ALTERNATIVE GAGE TECHNIQUES ARE DESIRABLE. THE ELECTROMAGNETIC TECHNIQUE, WHICH DEPENDS RIGOROUSLY UPON FARADAY'S THEORY OF INDUCTION, HAS THE POTENTIAL OF BEING LESS SENSITIVE TO ADVERSE SHOCK, RADIATION, THERMAL AND EMP EFFECTS. IT IS PROPOSED TO MODIFY, IMPROVE AND HARDEN A VARIETY OF EXISTING ELECTROMAGNETIC GAGE DESIGNS SO THAT SUCH GAGES MAY BE SUCCESSFULLY DEPLOYED IN HES, AND POSSIBLY NUCLEAR, TESTS. THE PROPOSED EFFORTS WOULD BE FOCUSED UPON DEVELOPING IMPROVED TECHNIQUES FOR GENERATING THE MAGNETIC FIELDS REQUISITE FOR GAGE FUNCTIONING, NEW GAGE SENSING ELEMENT DESIGNS AND DATA ACQUISITION AND REDUCTION TECHNIQUES.