Experimental studies of the spatial distribution of neutron production around a thick lead target irradiated by 0.9 GeV protons

This study is part of a complex research of accelerator driven transmutation technologies (ADTT) carried out by a collaboration of the NPI ASCR in Rez with the JINR in dubna. The aim of the experiment was to check the validity of the model descriptions and the cross-section libraries used in the corresponding monte-carlo simulations of spallation reactions, and the propagation of the produced high-energy neutrons passed through a thick target. The experiment was carried out at the synchrophasotron of the laboratory for high energies at the JINR. Relativistic protons with an energy of 885 MeV interacting with a massive cylindrical lead target produced the spallation neutrons. The spatial and energetic distributions of the produced neutron field were measured by the activation of Al, Cu and Au foils placed on the surface of and next to the target. The HPGe detectors then measured the activity of the foils. The resulting γ-spectra of the activated foils were analysed, the yields of the corresponding radioactive nuclei were determined, and compared with monte-carlo based simulations performed both with the LAHET+MCNP code and the MCNPX code. (orig.)