Authors: Jeongbhin Seo (LANL), Fan Guo (LANL), Daniel Reisenfeld (LANL), Eric Zirnstein (UAH), Jacob Heerikhuisen (UAH), Sung Jun Noh (New Mexico Consortium))

Energetic neutral atoms (ENAs), observed by IBEX and now being measured by IMAP, provide a key remote-sensing probe of the global heliosphere, but their interpretation depends critically on the pickup-ion (PUI) distribution in the outer heliosphere. We present recent progress in the LANL global heliosphere model, which couples MHD plasma, kinetic neutral hydrogen, and a particle-based treatment of PUIs directly tied to charge-exchange events. Newly created PUIs are injected at their local production sites with velocities inherited from their parent neutrals, allowing the model to retain the spatially varying source structure. We further incorporate PUI processing at the termination shock, including shock heating and acceleration, to construct a more physically motivated downstream PUI distribution for ENA calculations. Using this framework, we examine how charge exchange, shock-processed PUIs, and heliosheath transport shape the spatial and energy distributions of PUIs and the resulting ENA emission.