The Advanced Light Source (ALS) is a specialized particle accelerator that generates bright beams of x-ray light for scientific research. Electron bunches travel at nearly the speed of light in a circular path, emitting ultraviolet and x-ray light in the process. The light is directed through about 40 beamlines to numerous experimental endstations, where scientists from around the world ("users") can conduct research in a wide variety of fields, including materials science, biology, chemistry, physics, and the environmental sciences. Operation of the ALS is funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences program.