Spallation neutron spectrum on a massive lead/paraffin target irradiated with 1 GeV protons

摘要

The gamma-ray spectra emitted by decaying of residual nuclei produced by spallation neutrons in (n, xn), (n, xnyp), (n, p), (n, gamma) reactions with activation threshold detectors, i.e. Bi-209, Au-197, Co-59, In-115, Th-232, were measured in the Laboratory of Nuclear Problems (LNP), JINR, Dubna, Russia. Spallation neutrons were generated by bombarding a 20 cm long cylindrical lead target with 8 cm diameter surrounded by a 6 cm thick layer of paraffin moderator with 1 GeV proton beam from the NUCLOTRON accelerator. Reaction rates and a spallation neutron spectrum were measured and compared with CASCADE code calculations.