Brookhaven's National Synchrotron Light Source II will use six damping wigglers, one pictured above, which will make the new facility one of the brightest synchrotron light sources in the world. The wiggler makes the electron beam more uniform and straight, producing brighter emissions and creating a broad spectrum of light. When completed, NSLS-II will be the world's leading storage-ring-based synchrotron light source. Scheduled for completion in 2015, NSLS-II will allow the characterization of the atomic and electronic structure, chemical composition, and magnetic properties of materials in a wide range of temperatures and environments. Its unique aspects will help researchers explore solutions to the grand energy challenges faced by the nation, and open up new regimes of scientific discovery. A synchrotron is a particular type of cyclic particle accelerator (atom smasher), descended from the cyclotron, in which the guiding magnetic field (bending the particles into a closed path) is time-dependent, being synchronized to a particle beam of increasing kinetic energy.