Abstract
The neutron flux of the n_TOF facility at CERN was measured, after installation of the new spallation target, with four different systems based on three neutron-converting reactions, which represent accepted cross sections standards in different energy regions. A careful comparison and combination of the different measurements allowed us to reach an unprecedented accuracy on the energy dependence of the neutron flux in the very wide range (thermal to 1 GeV) that characterizes the n_TOF neutron beam. This is a pre-requisite for the high accuracy of cross section measurements at n_TOF. An unexpected anomaly in the neutron-induced fission cross section of 235U is observed in the energy region between 10 and 30keV, hinting at a possible overestimation of this important cross section, well above currently assigned uncertainties.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
G. Wallerstein et al., Rev. Mod. Phys. 69, 995 (1997).
F. Käppeler, R. Gallino, S. Bisterzo, Wako Aoki, Rev. Mod. Phys. 83, 157 (2011).
N. Colonna et al., Energy Environ. Sci. 3, 1910 (2010).
OECD/NEA WPEC Subgroup 26 Final Report, Uncertainty and Target Accuracy Assessment for Innovative Systems Using Recent Covariance Data Evaluations, http://www.nea.fr/html/science/wpec/volume26, NEA No. 6410 (2008).
E. Chiaveri et al., J. Kor. Phys. Soc. 59, 1620 (2011).
C. Guerrero et al., Eur. Phys. J. A 49, 27 (2013).
A.D. Carlson, Metrologia 48, S328 (2011).
International Atomic Energy Agency, International Evaluation of Neutron Cross-Section Standards (Vienna, 2007).
S. Marrone et al., Nucl. Instrum. Methods A 517, 389 (2004).
I. Giomataris et al., Nucl. Instrum. Methods A 376, 29 (1996).
S. Andriamonje et al., J. Kor. Phys. Soc. 59, 1597 (2011).
D.B. Gayther, Metrologia 27, 221 (1990).
C. Paradela et al., Phys. Rev. C 82, 034601 (2010).
D. Tarrío et al., Phys. Rev. C 83, 044620 (2011).
I. Giomataris, R. De Oliveira, Method for fabricating an amplification gap of an avalanche particle detector, Patent CEA-CERN, Application Number 09 290 825.0 (2009).
U. Abbondanno et al., Nucl. Instrum. Methods A 538, 692 (2005).
S. Agostinelli et al., Nucl. Instrum. Methods A 506, 250 (2003).
F.J. Hambsch, I. Ruskov, Nucl. Sci. Eng. 163, 1 (2009).
G. Lorusso et al., Nucl. Instrum. Methods A 532, 622 (2004).
L.S. Waters et al., AIP Conf. Proc. 896, 81 (2007).
D. Tarrío, Neutron-induced fission fragment angular distribution at CERN n_TOF: The Th-232 case, PhD thesis (2012).
M. Calviani et al., Phys. Rev. C 80, 044604 (2009).
A. Ferrari, Fluka: A multi-particle transport code, Technical Report CERN-2005-010, INFN/TC_05/11, SLAC-R-773 (2005).
M.B. Chadwick et al., Nucl. Data Sheets 112, 2887 (2011).
K. Shibata et al., J. Nucl. Sci. Technol. 48, 1 (2011).
M. Jandel et al., Phys. Rev. Lett. 109, 202506 (2012).
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by P. Woods
Rights and permissions
About this article
Cite this article
Barbagallo, M., Guerrero, C., Tsinganis, A. et al. High-accuracy determination of the neutron flux at n_TOF. Eur. Phys. J. A 49, 156 (2013). https://doi.org/10.1140/epja/i2013-13156-x
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1140/epja/i2013-13156-x