A NEW HIGH ENERGY RADIATION DETECTOR

MANY TYPES OF RADIATION DETECTORS ARE AVAILABLE FOR NUCLEAR PHYSICS RESEARCH. NONE OF THEM HAVE COMBINED CHARACTERISTICS OF EXTREMELY FAST RESPONSE, GOOD ENERGY RESOLUTION, AND ADAPTABLE DETECTOR GEOMETRY. A DETECTOR WITH THESE PROPERTIES COULD PROVIDE THE KEY FOR SIGNIFICANT ADVANCEMENTS IN NUCLEAR PHYSICS RESEARCH. A SILICON-BASED POLYMER THAT HAS HIGHER ATOMIC NUMBER (Z), HIGHER DENSITY THAN ORGANIC SCINTILLATORS, AND A FASTER RESPONSE THAN BOTH ORGANIC AND INORGANIC MATERIALS HAS BEEN UNDER INVESTIGATIONAS A SCINTILLATOR. THIS MATERIAL SYSTEM HAS THE POTENTIAL TO PROVIDE AN INNOVATIVE SOLUTION TO THE PROBLEM OF DEVELOPING AN EXTREMELY HIGH SPEED, HIGH ENERGY RESOLUTION DETECTOR. PRELIMINARY RESULTS WITH THESE SILICON-BASED POLYMERS INDICATE THAT THEY ARE FASTER THAN THE BETTER ORGANIC FLUORS. AS SOLVENTS, THESE POLYMERS HAVE LOWER IONIZATION POTENTIALS THAN AROMATIC LIQUIDS, A CHARACTERISTIC THAT IS INDICATIVE OF HIGH PHOTON YIELDS. INITIAL PHOTOPHYSICAL AND IONIZING RADIATION EXPERIMENTS SHOW A PERFORMANCE CAPABILITY SUPERIOR TO ORGANIC SCINTILLATORS, WITH IMPROVED PROCESSING TECHNIQUES ALREADY DEFINED TO FURTHER IMPROVE PERFORMANCE. THE CHEMICAL SYNTHESIS TECHNIQUE USED TO MAKE THE HOST MOLECULE IS AMENABLE TO THE GRAFTING OF HIGH ATOMIC WEIGHT MOLECULES TO THE SILICON BACKBONE. IF THIS GRAFTING PROCESS IS ACCOMPLISHED WITHOUT SIGNIFICANT IMPAIRMENT TO THE SCINTILLATING PROPERTIES OF THE PARENT MOLECULE, THE HIGH Z PROPERTIES OF THE RESULTANT MOLECULES SUGGEST THAT AN ENERGYRESOLUTION CAPABILITY SUPERIOR TO A SODIUM IODIDE DETECTOR CAN BE ACHIEVED. THE RESULT CAN BE EXPECTED TO BE A SUPERIOR SCINTILLATING DETECTOR. CHEMICAL SYNTHESIS OF HIGHZ MOLECULES GRAFTED ONTO THE SILICON POLYMER IS INCLUDED IN PHASE I OF THIS PROJECT. PHOTOPHYSICAL CHARACTERIZATION OF THE RESULTANT MOLECULE WILL BE ACCOMPLISHED AND IONIZING RADIATION EXPERIMENTS ARE ALSO INCLUDED.