Evolution of Pickup Ions the Outer Heliosheath

Fluxes of Energetic Neutral Atoms (ENAs) with energies greater than 1 KeV measured by the Interstellar Boundary Explorer (IBEX) are predominantly created by charge exchange of interstellar neutral atoms with hot, non-thermal pickup ions (PUI). Of special importance is a narrow ``ribbon'' of an enhanced ENA flux most clearly seen around energies of 1 keV discovered by IBEX. While the origin of this ribbon is still under debate, various models attribute it to charge exchange between the LISM neutral atoms and PUIs near the heliopause. If PUI velocity distribution function preserves anisotropy until the next charge exchange occurs, the ribbon flux will be arriving predominantly from line-of-sight directions nearly perpendicular to the interstellar magnetic field lines draped around the heliopause. In this talk, we will review aspect of PUI dynamics relevant to the ribbon formation processes, placing particular emphasis on such questions as the origin and stability of PUI distributions under varying conditions and the evolution of turbulence generated by PUIs.