Mapping of the thermal neutron distribution in the lead block assembly of the PS-211 experiment at CERN, using thermoluminescence and nuclear track detectors

The main purpose of the TARC (transmutation by adiabatic resonance crossing) experiment (PS-211), was to demonstrate the possibility to destroy efficiently long-lived fission fragments (LLFF) in accelerator driven systems (ADS). The experimental set-up which consisted of a lead block with dimensions 3.3 * 3.3 * 3 m/sup 3/, was installed in a CERN proton synchrotron (PS) beam line. The proton beam at 2.5 GeV/c and 3.5 GeV/c, was incident in the centre of the lead block assembly producing neutrons via spallation reactions. Neutron flux measurements are presented in the lead block assembly using thermoluminescence and nuclear track detectors. The results are in good agreement with Monte Carlo calculations as well as with the results of the other methods used in the framework of the TARC experiment. (5 refs).