FIBER OPTIC ELECTRIC FIELD SENSORS FOR USE IN HARSH RADIATION ENVIRONMENTS

FIBER OPTICE ELECTRIC FIELD MEASUREMENT SYSTEMS OFFER ELECTROMAGNETIC PULSE AND ELECTROMAGNETIC INTERFERENCE IMMUNITY THAT IS NOT PROVIDED BY STANDARD ELECTRON BASED INSTRUMENTATION. TO DATE FIBER OPTIC BASED ELECTRIC FIELD MEASUREMENT SYSTEMS HAVE BEEN USED MOSTLY IN ABOVEGROUND TEST APPLICATIONS. IN THE UNDERGROUND TEST ENVIRONMENT, SENSORS ARE EXPOSED TO A HARSH RADIATION ENVIRONMENT. TECHNIQUES HAVE BEEN DEMONSTRATED THAT COMPENSATE FOR THE TRANSIENT LIGHT PRODUCTION AND OPTICAL ATTENUATION EFFECTS ASSOCIATED WITH RADIATION ENVIRONMENT. HOWEVER, NO ADEQUATE TECHNIQUE HAS BEEN DEVELOPED TO COMPENSATE FOR THE IONIZING RADIATION INDUCED SURFACE CHARGE BUILDUP ON DIELECTRIC SENSOR HEADS. THIS PROOPSAL ADDRESSES THE DEVELOPMENT OF A TECHNIQUE TO COMPENSATE FOR SURFACE CHARGE BUILDUP. IF SUCCESSFUL, FIBER OPTIC ELECTRIC FIELD MEASUREMENT SYSTEMS SUITABLE FOR USE IN HARSH RADIATION ENVIRONMENTS WILL BE AVAILABLE TO SUPPORT DNA TEST APPLICATIONS. IN THE PROPOSED PHASE I PROGRAM, THE REQUIREMENTS FOR ELECTRIC FIELD MEASUREMENT SYSTEMS FOR USE IN UNDERGROUND TESTS WILL BE ASSESSED. EXPERIMENTS WILL BE PERFORMED TO DEMONSTRATE THE PROPOSED TECHNIQUE'S ABILITY TO ACCURTELY MEASURE ELECTRIC FIELD IN THE PRESENCE OF TIME VARYING SURFACE CHARGE BUILDUP ON THE SENSOR HEAD. IN ADDITIONA, DETAILED MECHANICAL DESIGNS FOR FIBER OPTIC ELECTRIC FIELD SENSORS FOR USE IN UNDERGROUND TESTS WILL BE DEVELOPED.