TWO-PHOTON PHOTODISSOCATION IMAGING OF WATER VAPOR TO MEASURE HYDROGEN/AIR MIXING IN HYPERSONIC PROPULSION

THE PRESENCE OF WATER VAPOR PROVIDES AN INDICATION OF THE RAPID MIXING OF HYDROGEN AND AIR IN HYPERSONIC PROPULSION ENGINES. THIS IS A CRITICAL ISSUE WHICH CAN BE ADDRESSED BY NONINTRUSIVE IMAGING OF WATER VAPOR TO EVALUATE EFFICIENT FULE/AIR MIXING APPROACHES FOR SCRAMJETS. RECENTLY, TWO-PHOTON PHOTODISSOCIATION OF WATER VAPOR HAS BEEN INDUCED BY A KRF EXCIMER LASER AT 248 NM. THE FLUORESCENCE FROM THIS PROCESS CAN BE MEASURED TO DETECT WATER VAPOR QUANTITATIVELYAND NONINTRUSIVELY. IN THIS WORK, WATER VAPOR IMAGING BY TWO-PHOTON PHOTODISSOCIATION WILL BE EVALUATED USING A NARROWBAND, TUNABLE KRF EXCIMER LASER. OPTIMAL STRATEGIES FOR SINGLE AND MULTIPOINT MEASUREMENT OF WATER VAPOR WILL BE DETERMINED SUCH AS PUMPING WAVELENGTH, DETECTION WAVELENGTH, DETECTION OPTICS, AND CAMERA. THE AIM OF THE WORK IS TO DEVELOP A NEW, RELIABLE, RUGGED, QUANTITATIVE IMAGING DETECTOR FOR WATER VAPOR.