Advanced Photon Source

An Office of Science National User Facility

Supported Techniques

Overview of 12BM Experimental Setups:

Supported Techniques

On 12BM-B we have multiple supported techniques. These techniques include:

XAS (X-ray Absorption fine structure)
X-ray absorption fine structure (XAFS) is a method used to gather information regarding the geometric and electronic structure of the materials under study by using x-rays to penetrate deep into the absorbing atoms core electrons which then give off an x-ray absorption spectrum (absorption edge). This edge data can be used to understand the elemental structure of the samples under question.

General set up at 12BM:

XAS Setup

Diffraction (Reflectivity, Surface Scattering)

Diffraction (X-ray crystallography) is an experimental tool used to understand and measure the atomic and molecular structure of crystals. The X-ray beam diffracts in predictable ways when it hits the atoms of a crystalline structure. In an experiment the angles and intensities of the diffracted beam are measured which then can be used to produce a 3D picture of the density of electrons in the crystal being studied. The average position of the atoms in the crystal can be understood using the density of electrons picture built from the data along with the chemical bonds of the crystal and other information can be extraced as well.

General set up at 12BM:

Diffraction Setup

SAXS / WAXS (Small/Wide Angle X-ray Scattering)

Small-angle X-ray scattering (SAXS) is a nondestructive method used to characterize structures of solid and fluid constituents in the nanometer (nm) range. The technique utilizes the very low angle elastic scattering of x-rays to probe the inhomogeneities of the electron density on the scale of normally 1 – 100nm, giving structural information of the samples being evaluated. By recording the very small angles of scattering one can extract information regarding the shape and size of the molecular structure of the material being investigated.

General set up at 12BM:

SAXS Setup