Publication:
The Generalized Centroid Difference method for lifetime measurements via gamma-gamma coincidences using large fast-timing arrays.

Loading...
Thumbnail Image
Full text at PDC
Publication Date
2015
Authors
Mach Henryk, Andrzej
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
EDP Sciences
Citations
Google Scholar
Research Projects
Organizational Units
Journal Issue
Abstract
A novel method for direct electronic "fast-timing" lifetime measurements of nuclear excited states via gamma-gamma coincidences using an array equipped with N very fast high-resolution LaBr3(Ce) scintillator detectors is presented. The generalized centroid difference method provides two independent "start" and "stop" time spectra obtained without any correction by a superposition of the N(N - 1)/2 calibrated gamma-gamma time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific gamma-gamma cascade and the centroid difference as the time shift between the centroids of the two time spectra provides a picosecond-sensitive mirror-symmetric observable of the set-up. The energy-dependent mean prompt response difference between the start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing array mean gamma-gamma zero-time responses can be determined for 40 keV < E-gamma < 1.4 MeV with a precision better than 10 ps using a Eu-152 gamma-ray source. The new method is described with examples of (n,gamma) and (n,f,gamma) experiments performed at the intense cold-neutron beam facility PF1B of the Institut Laue-Langevin in Grenoble, France, using 16 LaBr3(Ce) detectors within the EXILL&FATIMA campaign in 2013. The results are discussed with respect to possible systematic errors induced by background contributions.
Description
© Owned by the authors, published by EDP Sciences, 2015. ESSN: 2100-014X Artículo firmado por 31 autores. This work was supported by NuPNET, by contracts 05P12PKNUF and 05P12RDNUP of the German BMBF, by contract DNC7RP01/4 of the British STFC and by the Spanish MINECO projects FPA2010-17142, CPAN (CSD 2007-00042) and PRI-PIMNUP-2011-1338 (via the ERA-NET NuPNET call for translational joint activities). The EXILL&FATIMA campaign would not have been possible without the support of several services at the ILL and the LPSC. We are grateful to the EXOGAM collaboration for the loan of the detectors, to GANIL for assistance during installation and dismantling and to the FATIMA collaboration for the use of the LaBr3(Ce)-scintillator detectors. International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS15) (15. 2014. Dresden, Alemania).
UCM subjects
Keywords
Citation
[1] W. D. Hamilton, The electromagnetic interaction in nuclear spectroscopy, North-Holland New York 1975, 173 [2] H. Mach, R. L. Gill, M. Moszynski, Nuclear Instruments and Methods in Physics Research Section A 280, 49 (1989) [3] J.-M. Régis, et al., Nuclear Instruments and Methods in Physics Research Section A 622, 83 (2010) [4] A. Dewald, S. Harissopulos, P. von Brentano, Zeitschrift für Physik A 334, 163 (1989) [5] A. Winther, K. Alder, Amsterdam, North-Holland 1975; New York, American Elsevier 1975 [6] Z. Bay, Physics Review 77, 419 (1950) [7] H. Mach, et al., Nuclear Physics A 523, 197 (1991) [8] J.-M. Régis, et al., Nuclear Instruments and Methods in Physics Research Section A 684, 36 (2012) [9] J.-M. Régis, et al., Nuclear Instruments and Methods in Physics Research Section A 726, 191 (2013) [10] G. de France, et al., EPJ Web of Conferences 66, 02010 (2014) [11] H. Abele, et al., Nuclear Instruments and Methods in Physics Research Section A 562 407 (2006) [12] W. Urban, et al., Journal of Instrumentations 8, P03014 (2011) [13] J.-M. Régis, et al., Nuclear Instruments and Methods in Physics Research Section A 763, 210 (2014) [14] A. Kuronen, et al., Nuclear Physics A 549, 59 (1992) [15] B. Singh, Nuclear Data Sheets 109, 297 (2008) [16] J. Jolie, et al., these proceedings [17] J. Jolie, et al., Journal of Physics: Conf. Ser. 533, 012026 (2014) [18] S. Ilieva, et al., submitted.