March 2000 issue
This Compton Award ceremony speech at the Advanced Photon Source presents an overview of how cryogenically cooled monochromator optics have been developed to provide brilliant beams from hard X-ray undulators.
A vacuum-compatible monochromatic beam-position monitor using PIN photodiodes is described, based on fluorescence generated by a thin metal foil placed in the full X-ray beam. The true beam centre-of-mass is measured with a position sensitivity of 1–2 µm.
Two bent-crystal monochromators for 100 keV and 300 keV X-rays have been developed at the wiggler beamline BL08W of SPring-8.
It is shown that a properly designed transversal groove machined into the surface of a single-crystal monochromator may concentrate the diffracted radiation meridionally. This arrangement should provide two-dimensional focusing of a diffracted synchrotron radiation beam.
The design and performance of the high-brilliance XAFS facility at BL10XU of SPring-8, aimed at rapid and sensitive measurement of X-ray absorption fine structure, is reported.
Thermal effects in extended X-ray absorption fine structure and X-ray photoelectron diffraction due to atomic vibration in cubic and quartic potentials are studied by use of Feynman's path-integral approach.
A conical slit for three-dimensional XRD mapping has been manufactured by wire-electrodischarge machining. An algorithm for alignment of the slit is established, and the potential of the technique is illustrated with an example of grain mapping in a 4.5 mm-thick Cu sample.
A specimen chamber is described for soft X-ray spectromicroscopy of hydrated specimens and solutions. Applications include imaging and carbon edge spectroscopy of hydrated clay/polymer suspensions.