Monte-Carlo simulations of the new LNHB manganese bath facility

The new manganese bath facility of the Laboratoire National Henri Becquerel has been modeled by using three Monte-Carlo codes: MCNPX, GEANT4, and FLUKA, in order to determine the correction factors needed in the neutron source calibration process. The most realistic source geometry has been determined, and the most reliable cross sections library has been chosen. The models were compared, and discrepancies between the codes have been pointed out. Potential causes of deviations between results were assessed and discussed using additional models. Finally, an experimental process is proposed to validate the accuracy of the different codes and their abilities in simulating the neutron capture by the manganese bath. ► We modeled the new LNHB manganese bath using MCNPX, GEANT4 and FLUKA. ► ENDFBVII.0 cross sections library with thermal scattering choice is discussed. ► Discrepancies between codes are studied and causes are pointed out. ► New experimental process for accuracy assessment of the codes is described. ► New inputs to the uncertainty budget of the manganese bath method.