Национальный источник синхротронного излучения при Брукхейвенской национальной лаборатории.

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) in Upton, New York was a national user research facility funded by the U. S. Department of Energy (DOE). Built from 1978 through 1984, and officially shut down on September 30, 2014, the NSLS was considered a second generation synchrotron. The NSLS experimental floor consisted of two electron storage rings: an X ray ring and a VUV (vacuum ultraviolet) ring which provided intense, focused light spanning the electromagnetic spectrum from the infrared through X rays. The properties of this light and the specially designed experimental stations, called beamlines, allowed scientists in many fields of research to perform experiments not otherwise possible at their own laboratories.

Ground was broken for the NSLS on September 28, 1978. The VUV ring began operations in late 1982 and the X ray ring was commissioned in 1984. In 1986, a second phase of construction expanded the NSLS by , which added offices, laboratories and room for new experimental equipment. During the Phase II upgrade in 1986, two insertion wigglers/undulators were added to the VUV ring, providing the highest brightness source in the vacuum ultraviolet region until the advent of 3rd generation light sources. The final lattice design was completed in 1978 and the first stored beam was obtained in September 1982. By 1985, the experimental program was in a rapid state of development, and by the end of 1990, the Phase II beamlines and insertion devices were brought into operation. These electrons then proceeded through a linear accelerator (linac), which got them up to 120 MeV.

The UV ring had 19 beamlines, while the X ray ring had 58 beamlines. The beamlines were operated and funded in numerous ways. However, since the NSLS was a user facility, any scientist that submitted a proposal could be granted beamtime after peer review. There were two types of beamlines at the NSLS: Facility Beamlines (FBs), which were operated by the NSLS staff and reserved a minimum of 50 percent of their beamtime for users, and Participating Research Team (PRT) beamlines, which were operated and staffed by external groups and reserved at least 25 percent of their beamtime for users. Each X ray beamline had an endstation called a hutch. These are large enclosures made of radiation shielding materials, such as steel and leaded glass, to protect the users from the ionizing radiation of the beam. On the X ray floor, many of the experiments conducted used techniques such as X ray diffraction, high resolution powder diffraction (PXRD), XAFS, DAFS (X ray diffraction anomalous fine structure), WAXS, and SAXS. On the VUV ring, the endstations were usually UHV (ultra high vacuum) chambers that were used to conduct experiments using methods such as XPS, UPS, LEEM, and NEXAFS. In some beamlines, there were other analytical tools used in conjunction with synchrotron radiation, such as a mass spectrometer, a high power laser, or a gas chromatography mass spectrometer. These techniques helped supplement and better quantify the experiments carried out at the endstation.

In 2003, Roderick MacKinnon won the Nobel Prize in Chemistry for deciphering the structure of the neuronal ion channel. His work was in part conducted at the NSLS. In 2009, Venkatraman Ramakrishnan and Thomas A. Steitz , and Ada E. Yonath won the Nobel Prize in Chemistry for imaging the ribosome with atomic resolution through their use of x ray crystallography at the NSLS and other synchrotron light sources.

The National Synchrotron Light Source hosted more than 2,200 users from 41 U. S. states and 30 other countries in 2009. In 2009, there were 658 journal publications and 764 total publications including journal publications, books, patents, thesis, and reports.

The NSLS was permanently shutdown on September 30, 2014, after more than 30 years of service.