NEXT GENERATION NEUTRON SCINTILLATORS BASED ON SEMICONDUCTOR NANOSTRUCTURES

Cai-Lin Wang

关键词: ABSORPTION;    DECAY;    IRRADIATION;    LIFETIME;    NANOSTRUCTURES;    NEUTRONS;    PARTICLE SIZE;    PHOSPHORS;    THERMAL NEUTRONS Neutron;    Scintillator;    Inorganic;   

DOI  :  10.2172/948092
RP-ID  :  DOEER84884-F
PID  :  OSTI ID: 948092
Others  :  TRN: US1000941

美国|英语

来源: SciTech Connect

【 摘 要 】

The results reported here successfully demonstrate the technical feasibility of ZnS QDs/{sup 6}LiF/polymer composites as thermal neutron scintillators. PartTec has obtained stable ZnS QDs with a quantum yield of 17% induced by UV light, and light pulse decay lifetimes of 10-30 ns induced by both UV and neutrons. These lifetime values are much shorter than those of commercial ZnS microparticle and {sup 6}Li-glass scintillators. Clear pulse height peaks induced by neutron irradiation were seen for PartTec's ZnS nanocomposites. By adjusting the concentrations, particle size and degree of dispersion of ZnS QD/{sup 6}LiF in a PVA matrix, the light absorption and light yield of films at 420-440 nm can be optimized. PartTec's novel scintillators will replace traditional {sup 6}Li-glass and ZnS/{sup 6}LiF:Ag scintillators if the PL quantum yield can be improved above 30%, and/or increase the transparency of present nanoscintillators. Time and resources inhibited PartTec's total success in Phase I. For example, bulk doping preparations of ZnS QDs with Ag{sup +}, Eu{sup 3+} or Ce{sup 3+} QDs was impractical given those constraints, nor did they permit PartTec to measure systematically the change of PL decay lifetimes in different samples. PartTec will pursue these studies in the current proposal, as well as develop a better capping and dopant along with developing brighter and faster ZnS QD scintillators.