ILC 3.2 km damping ring design based on the FODO cell

We report on a new design for an ILC 3.2 km damping ring, with 2 arcs based on the FODO cell and 2 straight sections that are nearly the same as the newest version of the 6.4 km ring DCO4. This new lattice requires fewer magnets and a lower RF voltage, and has a better dynamic aperture than DCO4 while maintaining flexibility in regard to the momentum compaction factor. So far, this design is the only one satisfying all the requirements for a 3.2 km ring. The work on the lattice design and the dynamic aperture study is presented in detail.