Neutron activation by neutrons produced via proton-induced spallation in aliquid-mercury target: Measurements and assessment of uncertainties

A preliminary test of a liquid mercury target for the production of neutron s by spallation was undertaken at the Alternating Gradient Synchrotron faci lity at Brookhaven National Laboratory. Neutron activation of elemental foi ls placed on the target demonstrates that a range of neutron energies does exist, as expected, and that the neutron flux is at a maximum 10-20 cm from the front of the target, moving deeper with increasing proton energy. Unce rtainties in the activity calculations are in general significantly <10%. I mpurities in some of the foils are a significant source of interference for some reactions, although there is no interference for most of the reaction s. The presence of many interference-free reactions, along with the low unc ertainties indicates that the foils will be useful benchmarks to validate t he neutronics codes utilized in the target design.