Modeling the LANL Ultracold neutron source

The ultracold neutron (UCN) source at LANL uses a solid deuterium UCN converter and is driven by pulsed spallation neutrons. This UCN source has been and is being used for various science experiments. An effort to further upgrade the UCN source is currently underway. An extensive source modeling has been performed. In this talk, the method and results of the modeling of the current and the upgraded sources, the insight gained by the modeling work, and the expected performance of the upgraded source will be presented.