Optimization and Fabrication of Hyperboloid Apertures for the BL3 Experiment

The large-diameter neutron beam in BL3 poses new challenges for neutron detection uniformity in the BL3 experiment. Hyperboloid shaped apertures are easily manufactured using a wire EDM machine and offer a promising way of reducing systematic uncertainties in the mean neutron lifetime associated with neutron detection uniformity to below the goal level of 0.1 seconds. In this talk, I will discuss the optimization/design process and compare the alignment sensitivity/performance of these apertures to the more standard planar apertures used in previous experiments.