The nonlinear light output of NaI(Tl) detectors in the Modular Total Absorption Spectrometer

Journal Article · Wed Apr 08 00:00:00 EDT 2015 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI:https://doi.org/10.1016/j.nima.2015.03.087· OSTI ID:1347303

Rasco, B. C. ^[1]; Fijałkowska, A. ^[2]; Karny, M. ^[2]; Rykaczewski, K. P. ^[3]; Wolińska-Cichocka, M. ^[4]; Grzywacz, R. ^[5]; Goetz, K. C. ^[5]

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1. Louisiana State Univ., Baton Rouge, LA (United States)
2. Univ. of Warsaw (Poland)
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Warsaw (Poland); Oak Ridge Associated Univ., Oak Ridge, TN (United States)
5. Univ. of Tennessee, Knoxville, TN (United States)

New detector array, the Modular Total Absorption Spectrometer (MTAS),was commissioned at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Lab(ORNL).Total absorption gamma spectra measured with MTAS are expected to improve beta-feeding patterns and beta strength functions in fission products.MTAS is constructed out of hexagonal NaI(Tl) detectors with a unique central module surrounded by 18 identical crystals assembled in three rings. The total NaI(Tl) mass of MTAS is over1000 kg.The response of the central and other 18 MTAS modules to -radiation was simulated using the GEANT4 tool kit modified to analyze the nonlinear light output of NaI(Tl).A detailed description oftheGEANT4modifications madeisdiscussed.SimulatedenergyresolutionofMTAS modules is found to agree well with the measurements for single transitions of 662keV (137Cs) with 8.2% full width half maximum (FWHM),835keV (54Mn) with FWHM of 7.5% FWHM, and 1115keV (65Zn) with FWHM of 6.5%.Simulations of single and multiple -rays from 60Co are also discussed.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Holifield Radioactive Ion Beam Facility (HRIBF)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC05-00OR22725; FG02-96ER40978
• OSTI ID: 1347303
• Alternate ID(s): OSTI ID: 1247389
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 788; ISSN 0168-9002
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
Beta decay
Total
absorption spectrometry
NaI(Tl)
Simulation
MTAS