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Title: Charge carrier and exciton dynamics in LaBr{sub 3}:Ce{sup 3+} scintillators: Experiment and model

Abstract

The scintillation yield and decay time of LaBr{sub 3} doped with 0.2%, 0.5%, and 5% cerium were studied between 80 K and 600 K. LaBr{sub 3}:5%Ce{sup 3+} on a photomultiplier tube shows at 300 K a very high scintillation yield of 22 800 photoelectrons per MeV (64 000 photons per MeV) with a decay time of 16 ns. At 600 K the yield decreases by {approx_equal}15%. The scintillation yield of LaBr{sub 3}:0.2%Ce{sup 3+} is 19 800 photoelectrons per MeV (56 000 photons per MeV) at 300 K with a decrease by {approx_equal}50% at 600 K and a main scintillation decay time around 30 ns. The appearance of slow components in the Ce emission indicates a relatively slow energy transfer from the host crystal to Ce. The presence or absence of slow components depends on both concentration and temperature. The results are analyzed and interpreted with a model that comprises prompt charge carrier trapping by Ce and delayed excitation of Ce by means of thermally activated transport of self-trapped exciton defects. The results of the study provide detailed information on the scintillation mechanism. Besides presenting experimental data, the different energy transfer processes are quantified.

Authors:
;  [1]
  1. Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629JB Delft (Netherlands)
Publication Date:
OSTI Identifier:
20951413
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 18; Other Information: DOI: 10.1103/PhysRevB.75.184302; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CERIUM; CERIUM IONS; CHARGE CARRIERS; DOPED MATERIALS; ENERGY TRANSFER; EXCITONS; EXPERIMENTAL DATA; GAMMA DETECTION; LANTHANUM BROMIDES; PHOTOMULTIPLIERS; PHOTONS; SCINTILLATIONS; SOLID SCINTILLATION DETECTORS; TEMPERATURE DEPENDENCE; YIELDS

Citation Formats

Bizarri, G., and Dorenbos, P. Charge carrier and exciton dynamics in LaBr{sub 3}:Ce{sup 3+} scintillators: Experiment and model. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.184302.
Bizarri, G., & Dorenbos, P. Charge carrier and exciton dynamics in LaBr{sub 3}:Ce{sup 3+} scintillators: Experiment and model. United States. doi:10.1103/PHYSREVB.75.184302.
Bizarri, G., and Dorenbos, P. Tue . "Charge carrier and exciton dynamics in LaBr{sub 3}:Ce{sup 3+} scintillators: Experiment and model". United States. doi:10.1103/PHYSREVB.75.184302.
@article{osti_20951413,
title = {Charge carrier and exciton dynamics in LaBr{sub 3}:Ce{sup 3+} scintillators: Experiment and model},
author = {Bizarri, G. and Dorenbos, P.},
abstractNote = {The scintillation yield and decay time of LaBr{sub 3} doped with 0.2%, 0.5%, and 5% cerium were studied between 80 K and 600 K. LaBr{sub 3}:5%Ce{sup 3+} on a photomultiplier tube shows at 300 K a very high scintillation yield of 22 800 photoelectrons per MeV (64 000 photons per MeV) with a decay time of 16 ns. At 600 K the yield decreases by {approx_equal}15%. The scintillation yield of LaBr{sub 3}:0.2%Ce{sup 3+} is 19 800 photoelectrons per MeV (56 000 photons per MeV) at 300 K with a decrease by {approx_equal}50% at 600 K and a main scintillation decay time around 30 ns. The appearance of slow components in the Ce emission indicates a relatively slow energy transfer from the host crystal to Ce. The presence or absence of slow components depends on both concentration and temperature. The results are analyzed and interpreted with a model that comprises prompt charge carrier trapping by Ce and delayed excitation of Ce by means of thermally activated transport of self-trapped exciton defects. The results of the study provide detailed information on the scintillation mechanism. Besides presenting experimental data, the different energy transfer processes are quantified.},
doi = {10.1103/PHYSREVB.75.184302},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 18,
volume = 75,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}