Hadron multiplicity studies on a combined Pb/U-blanket spallation source: Experimental and simulation benchmark analysis

Spallation sources are able to produce intense neutron fluxes using massive targets when irradiated by relativistic proton beams. Such sub-critical Accelerator Driven Systems (ADSystem) can be used for transmutation or incineration of long-lived radioactive waste by neutron captures or neutron induced fission. In the present study a spallation source consisted of a combined Pb/U target was irradiated by relativistic proton beams from 0.7 up to 2 GeV. Neutron fluences were measured using passive detectors. A benchmark analysis was applied on the experimental results taken under consideration Monte Carlo simulation data of neutron multiplicity. In order to evaluate the tolerance of the structural materials in source design, the neutron and proton distributions escaping the source surface were measured. The spallation source performance in terms of neutron and proton production as well as the effectiveness of a polyethylene shielding surrounding the spallation source is also discussed.