# National Synchrotron Light Source II

The National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory (BNL) in Upton, New York is a national user research facility funded primarily by the U.S. Department of Energy's (DOE) Office of Science. NSLS-II is a synchrotron light source, designed to produce X-rays 10,000 times brighter than BNL's original light source, the National Synchrotron Light Source (NSLS). NSLS-II supports research in energy security, advanced materials synthesis and manufacturing, environment, and human health.

## Users and partners
### Users

In order to use the NSLS-II, researchers submit a peer-reviewed proposal. In the first five months of 2023, NSLS-II served over 1,200 researchers from academic, industrial, and government laboratories worldwide.

### Partners

NSLS-II has partners with public and private institutions which joined effort to fund the construction and operation of some of its beamlines. Its partnerships include BNL's Center for Functional Nanomaterials and the National Institute of Standards and Technology.

## Beamlines

NSLS-II currently has 29 beamlines (experimental stations) open for operations. When the facility is complete, NSLS-II is expected to "be capable of supporting some 58 beamlines in total."
The beamlines at NSLS-II are grouped into five science programs: hard X-ray scattering & spectroscopy, imaging and microscopy, structural biology, soft X-ray scattering and spectroscopy, and complex scattering. These programs group beamlines together that offer similar types of research techniques for studying the behavior and structure of matter.

### Hard X-ray scattering & spectroscopy

* 6-BM: Materials Measurement (BMM)
* 7-BM: Quick X-ray Absorption and Scattering (QAS)
* 8-ID: Inner Shell Spectroscopy (ISS)
* 27-ID: High Energy X-ray Diffraction (HEX) (under construction)
* 28-ID-1: Pair Distribution Function (PDF)
* 28-ID-2: X-Ray Powder Diffraction (XPD)

### Imaging and microscopy

* 3-ID: Hard X-ray Nanoprobe (HXN)
* 4-BM: X-ray Fluorescence Microprobe (XFM)
* 5-ID: Submicron Resolution X-ray Spectroscopy (SRX)
* 8-BM: Tender Energy X-ray Absorption Spectroscopy (TES)
* 9-ID: Coherent Diffraction Imaging (CDI) (under construction)
* 18-ID: Full-Field X-ray Imaging (FXI)

### Structural biology

* 16-ID: Life Science X-ray Scattering (LIX)
* 17-ID-1: Highly Automated Macromolecular Crystallography Beamline (AMX)
* 17-ID-2: Frontier Microfocusing Macromolecular Crystallography (FMX)
* 17-BM: X-ray Footprinting of Biological Materials (XFP)
* 19-ID: Biological Microdiffraction Facility (NYX)

### Soft X-ray scattering & spectroscopy

* 2-ID: Soft Inelastic X-ray Scattering (SIX)
* 7-ID-1: Spectroscopy Soft and Tender 1 (SST-1)
* 7-ID-2: Spectroscopy Soft and Tender 2 (SST-2)
* 21-ID-1: Electron Spectro-Microscopy ARPES (ESM-ARPES)
* 21-ID-2: Electron Spectro-Microscopy XPEEM (ESM-XPEEM)
* 22-IR-1: Frontier Synchrotron Infrared Spectroscopy (FIS)
* 22-IR-2: Magnetospectroscopy, Ellipsomentry and Time-Resolved Optical Spectroscopies (MET)
* 23-ID-1: Coherent Soft X-ray Scattering (CSX)
* 23-ID-2: In situ and Operando Soft X-Ray Spectroscopy (IOS)
* 29-ID-1: Soft X-ray Nanoprobe (SXN) (under construction)
* 29-ID-2: NanoARPES and NanoRIXS (ARI) (under construction)

### Complex scattering

* 4-ID: Integrated In-situ and Resonant Hard X-ray Studies (ISR)
* 10-ID: Inelastic X-ray Scattering (IXS)
* 11-ID: Coherent Hard X-ray Scattering (CHX)
* 11-BM: Complex Materials Scattering (CMS)
* 12-ID: Soft Matter Interfaces (SMI)

## Storage ring parameters

NSLS-II is a medium energy (3.0 GeV) electron storage ring designed to deliver photons with high average spectral brightness exceeding 10$^{21}$ ph/s in the 2–10 keV energy range and a flux density exceeding 10$^{15}$ ph/s in all spectral ranges. This performance requires the storage ring to support a very high-current electron beam (up to 500 mA) with a very small horizontal (down to 0.5 nm-rad) and vertical (8 pm-rad) emittance. The electron beam is stable in its position (<10% of its size), angle (<10% of its divergence), dimensions (<10%), and intensity (±0.5% variation).

### Storage ring lattice

The NSLS-II storage ring lattice consists of 30 double-bend achromat (DBA) cells that can accommodate at least 58 beamlines for experiments, distributed by type of source as follows:
* 15 low-beta ID straights for undulators or superconducting wigglers
* 12 high-beta ID straights for either undulators or damping wigglers
* 31 BM ports providing broadband sources covering the IR, VUV, and soft X-ray ranges. Any of these ports can alternatively be replaced by a 3PW port covering the hard X-ray range.
* 4 BM ports on large gap (90 mm) dipoles for very far-IR

### Radiation sources

Continuing the tradition established by the NSLS, NSLS-II radiation sources span a very wide spectral range, from the far infrared (down to 0.1 eV) to the very hard X-ray region (>300 keV). This is achieved by a combination of bending magnets, three-pole wigglers, and insertion device (ID) sources.

## History

Construction of NSLS-II began in 2009 and was completed in 2014. NSLS-II saw first light in October 2014. The facility cost $912,000,000 to build, and the project received the DOE's Secretary's Award of Excellence. Torcon Inc., headquartered in New Jersey, was the general contractor selected by the DOE for the project.