A neutron irradiation facility is being developed at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory for the purposes of measuring neutron reaction cross sections on radioactive targets and for radiation effects testing. Applications are of benefit to stockpile stewardship, nuclear astrophysics, next generation advanced fuel reactors, and cosmic radiation biology and electronics in space. The facility will supply a tunable, quasi-monoenergetic neutron beam in the range of 10-30 MeV or a white neutron source, produced by deuteron breakup reactions on thin and thick targets, respectively. Because the deuteron breakup reaction has not been well studied at intermediate incident deuteron energies, above the target Coulomb barrier and below 56 MeV, a detailed characterization was necessary of the neutron spectra produced by thin targets.Neutron time of flight (TOF) methods have been used to measure the neutron spectra produced on thin targets of low-Z (titanium) and high-Z (tantalum) materials at incident deuteron energies of 20 MeV and 29 MeV at 0 deg. Breakup neutrons at both energies from low-Z targets appear to peak at roughly half of the available kinetic energy, while neutrons from high-Z interactions peak somewhat lower in energy, owing to the increased proton energy due to breakup within the Coulomb field. Furthermore, neutron spectra appear narrower for high-Z targets. These centroids are consistent with recent preliminary proton energy measurements using silicon telescope detectors conducted at LBNL, though there is a notable discrepancy with spectral widths.

Advanced neutron interrogation systems for the screening of sea-land cargo containers for shielded special nuclear materials (SNM) require a high-yield neutron source to achieve the desired detection probability, false alarm rate, and throughput. An accelerator-driven neutron source is described that produces a forward directed beam of high-energy (up to 8.5 MeV) neutrons utilizing the D(d,n)3He reaction at deuteron beam energies of up to 6 MeV. The key components of the neutron source are a high-current RFQ accelerator and an innovative neutron production target. A microwave-driven deuteron source is coupled to an electrostatic LEBT that injects a 40 mA D+-beam into a 6 MeV, 5.1 meter-long, 200 MHz RFQ. The RFQ is based on an unusual beam dynamics design and is capable of operating at a duty factor that produces more than 1.2 mA timeaverage beam current. The beam is transported to a 2-atmosphere deuterium gas target with a specially-designed, thin entrance window. A high-frequency dipole magnet is used to spread the beam over the long dimension of the 4 by 35 cm target window. The source will be capable of delivering a neutron flux of ~;2 x 107 n/(cm2 x s) to the center of a sea-land cargo container and is expected t o satisfy the requirements for full testing and demonstration of advanced neutron interrogation techniques based on stimulated SNM signatures.