An Intense Pulsed Neutron Source for Argonne National Laboratory

A pulsed neutron source has been designed for materials research in slow neutron scattering and radiation effects. The facility is based in its first phase on the ZGS 500 MeV Injector Booster Accelerator, which will produce 5 × 1012 protons per pulse and be modified for 60 Hz operation. In its second phase a high intensity synchrotron will provide 5 × 1013 protons per pulse at 60 Hz at 600-800 MeV. Neutrons are produced by spallat ion in two targets. A 238U target surrounded by three hydrogeneous moderators provides 12 neutron beams for slow neutron spectrometers. Peak thermal neutron fluxes of 1.5 × 1015 and 1016 n/cm2 sec will be available in Phases I and II, respectively. Such pulsed beams will provide new capabilities for neutron scattering research, especially in the use of neutrons with energies up to 1 eV, which is beyond the capacity of the most advanced research reactors. A separate tungsten target for radiation effects studies provides fast neutrons (around 1 MeV) in 10 irradiation thimbles, with time-average fluxes around 3 × 1013 and 3 x 1014 n/cm2 sec in Phases I and II, respectively. The associated γ-ray flux is extremely low.