High-accuracy determination of the neutron flux in the new experimental area n_TOF-EAR2 at CERN
A new high flux experimental area has recently become operational at the n_TOF facility at CERN. This new measuring station, n_TOF-EAR2, is placed at the end of a vertical beam line at a distance of approximately 20m from the spallation target. The characterization of the neutron beam, in terms of flux, spatial profile and resolution function, is of crucial importance for the feasibility study and data analysis of all measurements to be performed in the new area. In this paper, the measurement of the neutron flux, performed with different solid-state and gaseous detection systems, and using three neutron-converting reactions considered standard in different energy regions is reported. The results of the various measurements have been combined, yielding an evaluated neutron energy distribution in a wide energy range, from 2meV to 100MeV, with an accuracy ranging from 2%, at low energy, to 6% in the high-energy region. In addition, an absolute normalization of the n_TOF-EAR2 neutron flux has been obtained by means of an activation measurement performed with 197Au foils in the beam.
- 2.OECD/NEA WPEC Subgroup 26 Final Report, Uncertainty and Target Accuracy Assessment for Innovative Systems Using Recent Covariance Data Evaluations, NEA No. 6410 (2008), http://www.nea.fr/html/science/wpec/volume26
- 11.ICRU, International Commission on Radiation Units and Measurements, report 60, issue 30, December 1998Google Scholar
- 19.I. Giomataris, R. De Oliveira, Patent CEA-CERN, Application Number 09 290 825.0 (2009), Method for fabricating an amplification gap of an avalanche particle detectorGoogle Scholar
- 22.D. Tarrío, Neutron-induced fission fragment angular distribution at CERN n_TOF: The Th-232 case, PhD Thesis (2012)Google Scholar
- 26.A. Fasso, Technical Report CERN-2005-10, INFN/TC_05/11, SLAC-R-73 (2005), Fluka: A multi-particle transport codeGoogle Scholar