TY - JOUR
T1 - The nonlinear light output of NaI(Tl) detectors in the Modular Total Absorption Spectrometer
AU - Rasco, B. C.
AU - Fijałkowska, A.
AU - Karny, M.
AU - Rykaczewski, K. P.
AU - Wolińska-Cichocka, M.
AU - Grzywacz, R.
AU - Goetz, K. C.
N1 - Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/7/11
Y1 - 2015/7/11
N2 - A 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 over 1000 kg. The response of the central and other 18 MTAS modules to γ-radiation was simulated using the GEANT4 toolkit modified to analyze the nonlinear light output of NaI(Tl). A detailed description of the GEANT4 modifications made is discussed. Simulated energy resolution of MTAS modules is found to agree well with the measurements for single γ transitions of 662 keV (137Cs) with 8.2% full width half maximum (FWHM), 835 keV (54Mn) with FWHM of 7.5% FWHM, and 1115 keV (65Zn) with FWHM of 6.5%. Simulations of single and multiple γ-rays from 60Co are also discussed.
AB - A 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 over 1000 kg. The response of the central and other 18 MTAS modules to γ-radiation was simulated using the GEANT4 toolkit modified to analyze the nonlinear light output of NaI(Tl). A detailed description of the GEANT4 modifications made is discussed. Simulated energy resolution of MTAS modules is found to agree well with the measurements for single γ transitions of 662 keV (137Cs) with 8.2% full width half maximum (FWHM), 835 keV (54Mn) with FWHM of 7.5% FWHM, and 1115 keV (65Zn) with FWHM of 6.5%. Simulations of single and multiple γ-rays from 60Co are also discussed.
KW - Beta decay
KW - MTAS
KW - NaI(Tl)
KW - Simulation
KW - Total absorption spectrometry
UR - https://www.scopus.com/pages/publications/84927947670
U2 - 10.1016/j.nima.2015.03.087
DO - 10.1016/j.nima.2015.03.087
M3 - Article
AN - SCOPUS:84927947670
SN - 0168-9002
VL - 788
SP - 137
EP - 145
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
ER -