Calculated Energy and Angular Dependence of Particle Fluxes at the Exit of the Advanced Neutron Source Radial and Tangential Beam Tubes

Calculational studies are conducted of neutron and gamma-ray transport in the beam tubes of a proposed high-flux reactor for the Advanced Neutron Source. To avoid excessively long computing times, the calculations were carried out by coupling two, two-dimensional discrete ordinates calculations. The calculational methodology used is briefly described. Calculated results are presented of the thermal neutron, nonthermal neutron, and gamma-ray fluxes in a radial and a tangential beam tube. Both scalar and angular fluxes in and at the exit of the beam tubes are given. When compared with the radial beam tube, the tangential beam tube shows a lower flux of high-energy neutrons and a much lower flux of gamma rays. The spectral characteristics of the particle fluxes at the exits of the beam tubes are similar to those at the entrances.