RUBY CRYSTAL CHLOROPHYLL FLUOROMETER FOR MEASUREMENTS OF PHOTOSYNTHESIS RATES

THE PURPOSE OF THIS PROPOSAL IS TO DESIGN, CONSTRUCT AND TEST A LABORATORY VERSION OF A PASSIVE CHLOROPHYLL FLUORESCENCE SENSOR SUITABLE FOR MONITORING LARGE AREAS OF VEGETATION (> 1 M2). THE LINE DISCRIMINATOR METHOD WE PROPOSE EXPLOITS A COINCIDENCE BETWEEN AN ABSORPTION LINE OFATMOSPHERIC OXYGEN AND THE R1 LINE OF A COOLED RUBY CRYSTAL,BOTH OF WHICH LIE NEAR THE PEAK OF THE CHLOROPHYLL FLUORESCENCE BAND. THE INSTRUMENT'S PERFORMANCE REGARDING SENSITIVITY AND FREEDOM FROM INTERFERENCE WILL BE EVALUATED QUANTITATIVELY. IT'S SUITABILITY FOR MAKING MEASUREMENTS OFPHOTOSYNTHESIS RATES WILL BE DETERMINED IN SMALL-SCALE (SINGLE LEAF) COMPARISON EXPERIMENTS FOR WHICH PROVEN FLUOROMETRIC INSTRUMENTATION AND PROCEDURES EXIST. THE RESULTS OF THE PHASE I EFFORT WILL RESOLVE CRITICAL DESIGN QUESTIONS AND PERMIT DEVELOPMENT OF A FIELD-READY PROTOTYPE FLUOROMETER IN PHASE II.