COMPOSITE HIGH TC SUPERCONDUCTIVE BOLOMETER

THE DISCOVERY OF THE NEW HIGH TEMPERATURE SUPERCONDUCTING (HTSC) OXIDES COUPLED WITH THE ADVENT OF DIAMOND THIN FILM GROWTH BY CHEMICAL VAPOR DEPOSITION TECHNIQUES HAVE OPENED UP THE POSSIBILITY OF A HIGH TEMPERATURE SUPERCONDUCTING TRANSITION EDGE BOLOMETER FOR USE AT SUBMILLIMETER WAVE LENGTHS. PRESENT DETECTOR TECHNOLOGY FOR THE SUBMILLIMETER WAVE REGION CONSISTS OF LOW SENSITIVITY, ROOM TEMPERATURE DETECTORS SUCH AS PYROELECTRICS, GOLAY CELLS AND THERMOPILES, AND VERY HIGH SENSITIVITY LOW TEMPERATURE DETECTORS SUCH AS SEMICONDUCTING AND SUPERCONDUCTIVE BOLOMETERS OR PHOTOCONDUCTORS. ALTHOUGH THE LATTER DETECTORS HAVE VERY LOW NOISE EQUIVALENT POWERS (NEP), THEY ARE NOT CONVENIENT TO USE BECAUSE THEY TYPICALLY OPERATE AT TEMPERATURES LESS THAN 1.5 DEGREES K. THE USE OF HIGH TCSUPERCONDUCTING THIN FILMS AND LOW THERMAL MASS, LOW REFRACTIVE INDEX DIAMOND FILMS NOW MAKES IT POSSIBLE TO CONSTRUCT A COMPOSITE BOLOMETER OPERATING IN THE TEMPERATURE RANGE 95-125 DEGREES K WITH A POTENTIAL NEP 10(-13) W/HZ (1/2). THE PURPOSE OF THIS PHASE I PROGRAM IS TO DEMONSTRATE THAT HIGH TC SUPERCONDUCTING THIN FILMS CAN BE DEPOSITED ON DIAMOND FILM SUBSTRATES AND THAT A NARROW SUPERCONDUCTING TRANSITION CAN BE OBTAINED. THE PHASE II PROGRAM WILL DEVELOP A PROTOTYPE COMPOSITE BOLOMETER FOR EVALUATION AS A SUBMILLIMETER WAVE DETECTOR.