Insertion device R&D for NSLS-II

NSLS-II is a medium energy storage ring of 3 GeV electron beam energy with sub-nm.rad horizontal emittance and top-off capability at 500 mA. Damping wigglers will be used not only to reduce the beam emittance but also for broadband sources for users. Cryo-permanent magnet undulators (CPMUs) are considered for hard X-ray planar device, and permanent magnet based elliptically polarized undulators (EPUs) are for soft X-ray polarization control. Rigorous R&D plans have been established to pursue the performance enhancement of the above devices as well as building new types of insertion devices such as high temperature superconducting wiggler/undulators. This paper describes the details of these activities and discuss technical issues.