NEW FAST HEAVY YAP SCINTILLATOR BASED PARTICLE DETECTORS

RESEARCHERS ARE DEVELOPING NUCLEAR/PARTICLE DETECTORS USING NEW FAST HEAVY INORGANIC SCINTILLATORS. THESE MATERIALS ARE OF TWO CLASSES: (1) BRIGHT CERIUM-ACTIVATED CRYSTALS - YAP, GAO, AND GSO - WHICH COULD DISPLACE THALLIUM DOPED SODIUM AND CESIUM IODIDE IN CERTAIN APPLICATIONS. THE CURRENT YAP CRYSTALS (UP TO 50 X 50 X 10 MM(3) HAVE MEASURED EFFICIENCIES, RESOLUTIONS, BRIGHTNESSES, AND MECHANICAL PROPERTIES COMPARABLE TO, OR BETTER THAN, THOSE OF SODIUM IODIDE BUT ARE ~10 TIMES FASTER; AND (2) DENSE UNDOPED LEAD TUNGSTENATE CRYSTALS WHICH OFFER AN ALTERNATIVE TO BISMUTH GERMANATE. RELATIVE TO BGO, THE CURRENT PWO CRYSTALS (UP TO 22 X 22 X 180 MM(3)) ARE ~12 PERCENT DENSER, ~10 TIMES FASTER, AND HAVE ~10 TIMES BETTER ENERGY RESOLUTION BUT ARE ONLY ~10 PERCENT AS BRIGHT.