Advanced Photon Source

Advanced Photon Source Argonne National LaboratoryArgonne National Laboratory

The Advanced Photon Source (APS) is a DOE scientific user facility at Argonne National Laboratory sponsored by the Basic Energy Sciences Program. APS provides ultra-bright, high-energy, storage-ring-generated X-ray beams for research in almost all scientific disciplines.

Unique properties of APS synchrotron radiation include its continuous X-ray spectrum, high flux and brightness, and high coherence, which make APS an indispensable tool for exploring matter. The wavelengths of its emitted photons can probe a range of sample dimensions from the atomic scale to entire cells and tissues, thereby providing incisive probes for advanced research in materials science, physical and chemical sciences, metrology, geosciences, environmental sciences, biosciences, medical sciences, and pharmaceutical sciences.

APS will be upgraded (APS-U) in 2023 to a multi-bend achromat lattice which will deliver the ultimate diffraction-limited X-ray source with radically transformative capabilities. The specific advantages of the APS-U X-ray source include:

  • Increased brightness allowing delivery of intense beams with dimensions of one micrometer or less, resulting in a 100-fold improvement in signal-to-noise.
  • Increased brightness at high energy (especially for energies 12 keV – 40 keV) that can be exploited to reduce primary radiation damage.
  • Low convergence X-ray beams essential to studying large macromolecular complexes at high resolution.

The expanded APS-U capabilities offer new opportunities such as tracking protein conformational changes in real time by simultaneously recording structural and kinetic data to understand correlations between molecular motions and chemistry in catalysis.

BER Resources at APS

The Structural Biology Center (SBC) is a resource for X-ray macromolecular crystallography (MX) and other complementary techniques. SBC research focuses on proteins relevant to BER missions (especially plant, fungal, and bacterial proteins) and on improving hardware and software for data collection at synchrotron beamlines.

Other APS Capabilities

APS offers more than 60 beamlines that can be applied to broad range of experimental conditions. The complete listing of contacts, specifications, and status for all APS beamlines is available on the APS website.

Three broad categories of experimental techniques are available at APS:

  • Scattering utilizes patterns of light produced when X-rays are deflected by the closely-spaced lattice of atoms in solids. This technique is commonly used to determine the structures of crystals and large molecules such as proteins.
  • Imaging techniques use the light-source beam to visualize samples at fine spatial resolutions. These techniques are applied in diverse research areas, including cell biology, lithography, infrared microscopy, radiology, and X-ray tomography.
  • Spectroscopy reveals the energies of particles emitted or absorbed by samples exposed to the light-source beam. This technique is commonly used to determine the characteristics of chemical bonding and electron motion.

SBC and other major research projects with a focus on biological systems, dynamics, synthetic biology, and structural biology take advantage of Argonne National Laboratory’s Advanced Protein Characterization Facility (APCF) located at Sector 84 of APS. APCF establishes state-of-the-art laboratories integrated with a scientific collaboration facility for protein production, characterization, and crystallization.

APCF efficiently delivers crystals to APS’ powerful X-ray beamlines and takes full advantage of Argonne’s facilities for determining three-dimensional structures of proteins and other biological macromolecules. APCF also characterizes protein functions and studies their interactions with other macromolecules and small ligands.