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Title: Scintillators with potential to supersede lanthanum bromide

New scintillators for high-resolution gamma ray spectroscopy have been identified, grown and characterized. Our development efforts have focused on two classes of high light yield materials: Europium-doped alkaline earth halides and Cerium-doped garnets. Of the halide single crystals we have grown by the Bridgman method - SrI{sub 2}, CaI{sub 2}, SrBr{sub 2}, BaI{sub 2} and BaBr{sub 2} - SrI{sub 2} is the most promising. SrI{sub 2}(Eu) emits into the Eu{sup 2+} band, centered at 435 nm, with a decay time of 1.2 {micro}s and a light yield of up to 115,000 photons/MeV. It offers energy resolution better than 3% FWHM at 662 keV, and exhibits excellent light yield proportionality. Transparent ceramics fabrication allows production of Gadolinium- and Terbium-based garnets which are not growable by melt techniques due to phase instabilities. While scintillation light yields of Cerium-doped ceramic garnets are high, light yield non-proportionality and slow decay components appear to limit their prospects for high energy resolution. We are developing an understanding of the mechanisms underlying energy dependent scintillation light yield non-proportionality and how it affects energy resolution. We have also identified aspects of optical design that can be optimized to enhance energy resolution.
Authors:
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Publication Date:
OSTI Identifier:
972276
Report Number(s):
LBNL-2449E
Journal ID: ISSN 0018-9499; IETNAE; TRN: US1001997
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Nuclear Science; Journal Volume: NS-56
Research Org:
Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
Sponsoring Org:
Life Sciences Division
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BRIDGMAN METHOD; CERAMICS; DECAY; DESIGN; ENERGY RESOLUTION; FABRICATION; GADOLINIUM; GARNETS; HALIDES; LANTHANUM BROMIDES; MONOCRYSTALS; PHOSPHORS; PRODUCTION; SCINTILLATIONS; SPECTROSCOPY