LOW-COST MICROSTRIP DETECTORS ON CONDUCTIVITY-MODIFIED KAPTON

DETECTORS FOR THE SUPERCONDUCTING SUPER COLLIDER (SSC) MUST HAVE EXTREME SPATIAL (30 MUM) AND TIME (15 NS) RESOLUTION. THE DETECTORS MUST OPERATE RELIABLY THROUGH TEMPERATURE AND HUMIDITY CHANGES IN HARSH RADIATION ENVIRONMENTS. GAS MICROSTRIP CHAMBERS, A SOLID-STATE REALIZATION OF TRADITIONAL WIRE-CHAMBER PROPORTIONAL DETECTORS, ARE UNDER DEVELOPMENT AT TEXAS A&M UNIVERSITY AND ELSEWHERE. THESE DETECTORS OFFER A TECHNOLOGY BREAKTHROUGH FOR MEETING THE STRINGENT REQUIREMENTS OF SSC. FUNCTIONING PROTOTYPE MICROSTRIP CHAMBERS HAVE BEEN FABRICATED ON GLASS AND SILICON SUBSTRATES. UNFORTUNATELY, COST, WEIGHT, AND STRENGTH LIMITATIONS MAKE THESE SUBSTRATES UNATTRACTIVE FOR SCALE-UP DEVELOPMENT. CONDUCTING POLYMER SUBSTRATES WOULD BE IDEAL EXCEPT THAT TRADITIONAL DOPING APPROACHES WOULD COMPROMISE THE ENVIRONMENTAL AND RADIATION TOLERANCE OF THE POLYMERS AND PRODUCE ERRATIC, NONOHMIC ELECTRICAL BEHAVIOR. AN ION IMPLANTATION PROCESS FOR RELIABLY CONTROLLING THE RESISTIVITY OF POLYAMIDE (KAPTON(TM)) SURFACES HAS BEEN DEVELOPED. PRELIMINARY TESTING SUGGESTS THAT THESE SURFACES WOULD BE IDEAL SUBSTRATES FOR GAS MICROSTRIP DETECTORS. IN PHASE I, PROTOTYPE DETECTOR SUBUNITS (10 CM X 10 CM) ARE BEING FABRICATED ON ION-IMPLANTED POLYAMIDE SUBSTRATES. IN COOPERATION WITH THE TEXAS A&M UNIVERSITY MICROSTRIP CHAMBER DEVELOPMENT GROUP, THIS PROJECT WILL MEASURE THE SPATIAL AND TIME RESOLUTION OF THESE PROTOTYPES AND EXPOSE THEM TO TEMPERATURE/HUMIDITY CYCLING AND TO COBALT-60 GAMMA IRRADIATION.