DEVELOPMENT OF NEW RADIATION RESISTANT LARGE STOKES SHIFTED INTRAMOLECULAR PROTON TRANSFER FLUORS

WE HAVE RECENTLY SHOWN THAT SILOXANE PLASTICS ARE EXCELLENT CANDIDATES AS A BASE FOR A RADIATION HARD SCINTILLATION DETECTOR AT THE SSC. IT IS ENVISAGED THAT SCINTILLATING PLASTIC WILL BE REQUIRED IN THE FORM OF FIBERS ABOUT 1MM DIAMETER FOR CALORIMETRY AND ABOUT 200 MICRONS FOR TRACING TRAJECTORY PARTICLES. FLUORS MUST BE DISSOLVED IN THE PLASTIC SUCH THAT THE LIGHT EMISSION OF THE PLASTIC AT 290 NM IS EFFICIENTLY ABSORBED BY THE FLUOR AND RE-EMITTED AT MORE THAN 450 NM. AT THE LATTER WAVELENGTH, THERE IS NEGLIGIBLE RADIATION DAMAGE TO THE PLASTIC AND HENCE THERE IS NO LOSS OF LIGHT TRANSMISSION WITH EXPOSURE OF THE FIBER TO RADIATION DOSES OF 10 MRAD OR MORE. DUE TO THE SMALL FIBER DIMENSIONS A SEQUENCE OF FLUORS TO SHIFT THE WAVELENGTH OF THE LIGHT IS INEFFICIENT. A SINGLE FLUOR WITH LARGE STOKES SHIFT IS HIGHLY DESIRABLE. EXISTING INTRAMOLECULAR PROTON TRANSFER (IMPT) FLUORS ACHIEVE THIS SHIFT BUT HAVE LOW QUANTUM EFFICIENCY ( 35%). LIGHT INTENSITY FROM 200 MICRONS FIBERS WILL BENEFIT GREATLY FROM THE PROPOSED NEW HIGH QUANTUM EFFICIENCY IMPT FLUORS. WE SUGGEST A TOTALLY NEW APPROACH TO THE DESIGN OF THE IMPT FLUORS WHICH SHOULD ALLOW THE SYNTHESIS OF MANY SUCH FLUORS,SOME WITH HIGH QUANTUM YIELD.