Imaging Group (X-ray Science Division)
The X-ray Imaging Group performs 2D and 3D x-ray imaging studies of dynamical phenomena, with spatial resolution ranging from a few micrometers to tens of nanometers, and time resolution ranging from a millisecond to hundreds of picoseconds. The group currently operates two beamlines at the APS, 2-BM dedicated to X-ray Micro Tomography and 32-ID dedicated to various full field imaging techniques using both absorption and phase contrast, including High-Speed Imaging, Real Time Radiography, Phase Contrast Imaging, Transmission X-ray Microscopy and nano-CT, and X-ray Micro-tomography. The Imaging group is also responsible for the design and construction of two new beamlines part of the APS-Upgrade project: the High Energy tomography beamline and the Wide Field Imaging beamline. The major research areas within the group are detailed below.
Nature Vol. 459 18 June 2009
2-BM X-ray Micro-tomography
The Imaging group operates a fully automated high-throughput micro-tomography system on its bending magnet beamline providing 3D imaging at 1µm resolution. This technique enables the determination of the distribution of physical quantities (density, porosity distribution, crack size etc.) in 3D on a large population of samples. The system is routinely used in new materials characterization, engineering material structural imaging, in biology and highly mineralized biological tissues, in geo-science and for industrial applications.
Xianghui Xiao’s research focuses on 3D dynamic experiments.
Nature Physics 4, 305 - 309 (2008)
32-ID-B High-Speed Imaging
Using the special operation (hybrid) modes of the APS, the High-Speed Imaging (HSI) technique takes advantage of the time structure of the filling pattern in the storage ring achieving exposure times set by the natural width of the x-ray pulses (down to 150 ps) and frame rates set by bunch repetition frequency (up to 271 kHz). These make this instrument a unique research tool for studying transient phenomena in hard and soft condensed matter, in systems far from equilibrium, including materials under extreme conditions (stress, heat, etc), failure of materials on impact, and the self-propagating exothermic reactions in metallic multilayers. In addition to phase-contrast imaging, other complementary techniques (such as diffraction and stereo-imaging) are being developed in order to be used simultaneously when adequate.
K. Fezzaa has been leading the HSI program, developing the capability and establishing and collaborating with a broad user community.
Proc. Nat. Acad. Sci. 104, 13198-13203 (2007)
32-ID-C Real Time Radiography and Phase Contrast Imaging
The Imaging group provides micrometer-range spatial resolution imaging in absorption or phase contrast modes over an energy range of 10-35 keV with data acquisition rates from 1 Hz to 3 kHz with a monochromatic beam. The scientific community of this instrument covers a broad range of disciplines: biologists looking at small animal physiology, material scientists looking at real time crack development, anthropologists looking at tooth development.Wah-Keat. Lee has been leading this effort at 32-ID using the real time radiography and phase constrast imaging system to study ferro-fluids.
32-ID-C Transmission X-ray Microscopy and nano-CT
The Transmission X-ray Microscope (TXM) and nano-CT system installed at 32-ID, provides full field imaging with up to 25 nm spatial resolution in the 8-15 keV energy range. This instrument currently leads the world’s hard x-ray imaging facilities in resolution, throughput, and in situ imaging capabilities. Both absorption and Zernike phase contrast modes are implemented. The research programs led by Steve Wang, include x-ray optics research and fabrication to push the resolution to 15 nm and elemental mapping and chemical speciation at 10 nm voxel level to be able to track dynamic evolutions of nano-scale and meso-scale phenomena. The research programs also include energy production and storage systems, material sciences, and biomedical imaging.