These techniques are used to study the energies of particles that are emitted or absorbed by samples that are exposed to the light-source beam and are commonly used to determine the characteristics of chemical bonding and electron motion.
In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed. The unifying feature is that some “property” of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy.
Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10–100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron–electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.
Soft x-ray spectroscopies employ the excitation of electrons in relatively shallow core levels (100–2000 eV) to probe the electronic structure of various kinds of matter. Elemental specificity is the watchword for this kind of spectroscopy. Each element has its own set of core levels that occur at characteristic energies. The photon-energy tunability of synchrotron radiation is essential.
Hard x-ray spectroscopy is applied in a wide variety of scientific disciplines (physics, chemistry, life sciences, and geology) to investigate geometric and electronic structure. The method is element-, oxidation-state-, and symmetry-specific. It is a primary tool in the characterization of new and promising materials. It is also used in the elucidation of dilute chemical species of environmental concern.
Beam line 7-3 is a wiggler side-station dedicated for x-ray absorption spectroscopy and EXAFS measurements on dilute biological systems. BL7-3 is equipped with a 30-element Ge solid-state detector in addition to ionization chambers and Lytle/PIPS detectors. A dedicated LHe cryostat allows for routine low temperature measurements. The unfocused beam on BL7-3 is ideal for samples especially susceptible to radiation damage, such as high-valent intermediates and other oxidized species.
After many years of service, the scattering capability is planned to be removed from bamline 7-2 after the first cycle of 2019 (March 2020). All of the wonderful capabilities our users have appreciated will be available at the new undulator scattering beamline BL 17-2 later in 2020.
Beam line 6-2c is a wiggler end-station dedicated to hard x-ray transmission x-ray microscopy. The BL6-2c back hutch houses a Transmission X-ray Microscope with 2D and 3D full field imaging and spectroscopic capabilities, with an instrument resolution down to 30 nm. It has specific capabilities for in-situ tomographic studies of catalytic processes including x-ray absorption spectroscopy.
Beam line 6-2b is a wiggler end-station dedicated to High Resolution Hard X-ray Spectroscopy. The end station combines three multicrystal Johann spectrometers that enable X-ray Emission Spectroscopy (XES), Resonant Inelastic X-ray Scattering (RIXS), High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy (HERFD-XAS) and X-ray Raman Spectroscopy (XRS) techniques.
Beam line 6-2a is a wiggler end-station that can be configured for tender x-ray x-ray emission spectroscopy (instrumentation in commissioning use).
Because BL5-2 and BL5-4 cannot operate simultaneously, they are often shown combined as BL5-4/BL5-2. Users may choose either experimental station for their beamtime. Please confirm with the responsible beam line scientists on the readiness of desired experimental station in advance.
Because BL5-2 and BL5-4 cannot operate simultaneously, they are often shown combined as BL5-4/BL5-2. Users may choose either experimental station for their beamtime. Please confirm with the responsible beam line scientists on the readiness of desired experimental station in advance.
Beam line 2-3 is a bending magnet side station dedicated to x-ray imaging and micro x-ray absorption spectroscopy (edge, EXAFS) as well as micro diffraction of biological, material, and geological samples. A set of SIGRAY axially symmetric mirror systems are used to achieve a microfocus with an option of a beam size of ~ 3 x 3 microns, or sub-micron spots. The energy range of the beam line optics covers 4.9-23 keV, with detection of fluorescent x-rays as low as Si. BL2-3 is equipped with a Vortex silicon drift detector and ionization chambers.
Beam line 2-2 is currently closed.
Beam line 4-1 is a high-flux station optimized for x-ray absorption spectroscopy and EXAFS experiments requiring x-rays with energies between ~ 6 and 38 keV. This energy range includes most of the transition metals (all rows), lanthanides and actinides, P-block elements, alkaline and alkaline earths. While it is possible to access x-rays as low as 5 keV, these experiments are challenging because of air absorption and are better performed at BL4-3.