GROUP II FLUORIDE COATED SCINTILLATING OPTICAL FIBERS

WE PROPOSE TO DEVELOP NOVEL INORGANIC SCINTILLATING FIBERS FOR USE IN IONIZING RADIATION IMAGING DETECTORS FOR RESEARCH, MEDICINE AND INDUSTRY, ESPECIALLY IN APPARATUS FORIMAGING X-RAYS, BETA AND ALPHA PARTICLES. IN PHASE I WE WILL USE METAL-ORGANIC CHEMICAL VAPOR DEPOSITION TECHNOLOGY TO COAT DISCRETE LENGTHS OF MECHANICALLY ROBUST QUARTZ OPTICAL FIBERS (SUBSTRATES) WITH THIN FILMS OF INORGANIC CAF2 OR BAF2 SCINTILLATORS. IN PHASE I, THE LUMINESCENT FILM THICKNESSES WILL RANGE BETWEEN 1 AND 10MU. THE SCINTILLATION LIGHT CREATED BY THE DEPOSITION OF IONIZING ENERGY IN THE SCINTILLATING FILM WILL BE TRAPPED AND PIPED IN THE RESULTING COMPOSITE OPTICAL FIBER STRUCTURE. THE POTENTIAL ADVANTAGES OF A CAF2 OR BAF2/QUARTZ COMPOSITE FIBERS OVER OTHER RADIATION IMAGING TECHNIQUES AND OVER EXISTING ORGANIC PLASTIC OR GLASS SCINTILLATING FIBERS ARE (A) VERY HIGH SPECIFIC LIGHT-OUTPUT, (B) POTENTIAL RADIATION-HARDNESS, (C) LONG TERM ENVIRONMENTAL STABILITY, (D) HIGH DE/DX, HIGH STOPPING POWER AND SHORT RADIATION LENGTH COMPARED TO PLASTIC, (E) LOW COST COMPARED TO SOME GLASSES, (F) HIGH SCINTILLATION SPEED COMPARED TO GLASS FIBERS (FOR BAF2), (G) POTENTIALLY LONG ATTENUATION LENGTHS OF THE EMITTED LIGHT PER UNIT PHOTON OUTPUT, ESPECIALLY COMPARED WITH PLASTIC SCINTILLATOR FIBERS, (H) HIGHLY UNIFORM AND PREDICTABLE PROPERTIES, AND (I) OPERATION IN VACUUM WITHOUT WINDOW MATERIAL. ADDITIONAL CLADDING, AS SUGGESTED BY PHASE I RESULTS, AND A CONTINUOUS MANUFACTURINGPROCESS FOR FIBER COATING WILL BE DEVELOPED IN PHASE II.