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BioCARS, a NIH-supported national user facility for macromolecular time-resolved X-ray crystallography at the Advanced Photon Source (APS), has recently completed commissioning of an upgraded undulator-based beamline optimized for single-shot laser-pump X-ray-probe measurements with time resolution as short as 100 ps. The source consists of two in-line undulators with periods of 23 and 27 mm that together provide high-flux pink-beam capability at 12 keV as well as first-harmonic coverage from 6.8 to 19 keV. A high-heat-load chopper reduces the average power load on downstream components, thereby preserving the surface figure of a Kirkpatrick–Baez mirror system capable of focusing the X-ray beam to a spot size of 90 µm horizontal by 20 µm vertical. A high-speed chopper isolates single X-ray pulses at 1 kHz in both hybrid and 24-bunch modes of the APS storage ring. In hybrid mode each isolated X-ray pulse delivers up to ∼4 × 1010photons to the sample, thereby achieving a time-averaged flux approaching that of fourth-generation X-FEL sources. A new high-power picosecond laser system delivers pulses tunable over the wavelength range 450–2000 nm. These pulses are synchronized to the storage-ring RF clock with long-term stability better than 10 ps RMS. Monochromatic experimental capability with Biosafety Level 3 certification has been retained.

Coherent hard x‐ray beams with a flux exceeding 109 photons/sec with a bandwidth of 0.1% will be provided by undulators at the third‐generation synchrotron radiation sources such as APS, ESRF, and Spring‐8. The availability of such high flux coherent x‐ray beams offers excellent opportunities for extending the coherence‐based techniques developed in the visible and soft x‐ray part of the electromagnetic spectrum to the hard x‐ray region. These x‐ray techniques (e.g., diffraction‐limited microfocusing, holography, interferometry, phase contrast imaging, and signal enhancement) may offer substantial advantages over noncoherence‐based x‐ray techniques currently used. For example, the signal‐enhancement technique may be used to enhance an anomalous x‐ray or magnetic x‐ray scattering signal by several orders of magnitude. Coherent x rays can be focused to a very small (diffraction‐limited) spot size, thus allowing construction of high spatial resolution microprobes. This paper will discuss the feasibility of e...

A polarimeter for x-ray and vacuum ultraviolet (XUV) radiation was built to measure the spatial and spectral dependence of the polarization of the light produced by the new undulator at the U5 beamline at NSLS. The fourth-harmonic radiation was measured, and it does not agree with predictions based on ideal simulation codes in the far-field approximation.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A zone plate capable of focusing hard x-rays to less than 1 {mu}m spot size is designed and specified. This design is based on the state-of-art fabrication technology available today. This zone plate consists of Cu/Al layers sputtered alternatively on a round stainless steel core. Parameters of this zone plate are given. The focal length f is given for 8Kev x-rays and the thickness is optimized for focusing efficiency of the same x-ray energy.

The magnetic structure and spectral properties of a 7.5‐cm, 30‐period hybrid undulator are described. The device will be installed at the U5 port of the VUV storge ring at Brookhaven National Laboratory and will be a tunable source of very high brillance soft x‐ray radiation over the range of 13 to approximately 150 eV.

The formation of ternary hydrides is often accompanied by significant changes in the structural, electronic and magnetic properties of the binary host intermetallic. Since Mossbauer spectroscopy is in essence a technique which probes the local structural, electronic and magnetic properties of the employed isotope, we used this technique to study the changes which occur in the ternary hydrides. Data from 57Fe, 161Dy, 166Er will be discussed and compared with results from other techniques.