1. The Generalized Centroid Difference method for lifetime measurements viaγ-γcoincidences using large fast-timing arrays
- Author
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F. Drouet, Zs. Podolyák, Aurelien Blanc, Alison Bruce, O. Stezowski, Gheorghe Pascovici, T. Kröll, W. Korten, T. Soldner, J.-M. Régis, S. Mărginean, Henryk Mach, N. Warr, Ulli Köster, J. Jolie, P.H. Regan, M. Rudigier, Paolo Mutti, G.S. Simpson, W. Urban, Michael Jentschel, V. Paziy, S. Lalkovski, M. Pfeiffer, C. A. Ur, A. Vancraeyenest, S. Ilieva, L. M. Fraile, N. Saed-Samii, A. Blazhev, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
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Physics ,business.industry ,QC1-999 ,Detector ,Centroid ,Observable ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,Scintillator ,Spectral line ,Computational physics ,Superposition principle ,Optics ,Cascade ,Excited state ,business - Abstract
This is an Open Access article distributed under the terms of the Creative Common Attribution Licence 4.0 which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.; International audience; A novel method for direct electronic "fast-timing" lifetime measurements of nuclear excited statesvia γ-γ coincidences using an array equipped with N very fast high-resolution LaBr3(Ce) scintillator detectorsis presented. The generalized centroid difference method provides two independent “start” and “stop” timespectra obtained without any correction by a superposition of the N(N − 1)/2 calibrated γ-γ time differencespectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forwardand reverse gating of a specific γ-γ cascade and the centroid difference as the time shift between the centroidsof the two time spectra provides a picosecond-sensitive mirror-symmetric observable of the set-up. The energydependentmean prompt response difference between the start and stop events is calibrated and used as a singlecorrection for lifetime determination. These combined fast-timing array mean γ-γ zero-time responses can bedetermined for 40 keV < Eγ < 1.4 MeV with a precision better than 10 ps using a 152Eu γ-ray source. Thenew method is described with examples of (n,γ) and (n,f,γ) experiments performed at the intense cold-neutronbeam facility PF1B of the Institut Laue-Langevin in Grenoble, France, using 16 LaBr3(Ce) detectors withinthe EXILL&FATIMA campaign in 2013. The results are discussed with respect to possible systematic errorsinduced by background contributions.
- Published
- 2015
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