Design of a new long counter for the determination of the neutron fluence reference values at the IRSN AMANDE facility

The Laboratory for Neutron Metrology and Dosimetry of the Institute for Radiation Protection and Nuclear Safety has undertaken a study related to the optimization of the geometry of a long counter to determine the neutron fluence reference values at the AMANDE facility. This study was performed on the basis of a De Pangher long counter design. The materials, the dimensions and the geometry were varied and the consequences on the response function were studied. Different parameters were optimized to flatten the neutron response energy distribution, over a wide energy range, from a few eV’s to a few MeV’s. The aim of this paper is to present the results of the study performed by using intensive Monte-Carlo simulations which helped in the design of the new IRSN long counter.