Neutron induced reactions in massive spallation targets

Abstract

Abstract During the last 15 years at JINR, Dubna a large number of experiments have been done to investigate the neutron field generated in big spallation targets. The Energy plus Transmutation project has two set-ups: big U/Pb [1] and Quinta [2,3]. These set-ups are irradiated by high energy deuteron and proton beams. The project continues with the next generation “quasi infinite target”, a cylinder of 21 tons of depleted uranium packed in a steel cage (the experiments have not been done yet) [4]. Such a target has simple requirements: all generated neutrons deliver more than 90% of their energy in the target volume and the leakage ranges between 5 and 10% of the generated neutrons. There is a significant number of experimental results and simulations with different transport codes MCNPX, FLUKA, GEANT 4 for big U/Pb target and Quinta set ups. The comparison of simulations with reaction rate measurements shows very good agreement with an error range of 10-20%. These results provided the basis for additional simulations for similar set-ups. In the big U/Pb set-up the lead target is replaced by natU and the polyethylene (PE) cage is replaced by natPb. Similar calculations are done with the Quinta set-up. The natPb shield is replaced with polyethylene (PE). The integral number of neutron induced reactions, neutron production and leakage are calculated and compared.