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Sector 16


16ID-A: Front-end optics enclosure showing the major components for beam conditioning and delivery. Foreground: High-heat-load slits and double-crystal  monochromator (water-cooled diamond 111) feeding x-rays to the mainline stations (ID-C,D,E). Background, left: Long vessel containing a 2.65m long rail on which the second crystal (Si 220) of the branching-monochromator travels. This monochromator delivers x-rays to ID-B, the side-station. HPCAT is the only beamline in the world with such a wavelength-tunable instrument which allows two stations to run concurrently.

 16ID-B: Geophysical Laboratory researchers Eugene Gregoryanz and Olga Degtreyava with HPCAT beamline scientist Maddury Somayazulu (right) during their recent high-pressure experiments on sulfur, mercury and nitrogen. Station ID-B uses a pair of state-of-the-art bimorph mirrors, unique in the USA, which focus a 0.5mm x 0.5mm x-ray beam into a 5μm x 7μm spot at the sample within the diamond anvil cell thereby delivering diffraction data untainted by the gasket material that contains the sample at Mbar pressures. ID-B is equipped with both a CCD-based detector and an Image-Plate reader to give scientists this world-unique flexibility of either fast data acquisition (CCD) or a large dynamic range (IP).

 16ID-C: Every photon counts in the revolutionary and challenging inelastic scattering experiments at high pressures. The two large ultra-high vacuum vessels shown in the photograph contain two meter-long mirrors which collect and focus the whole x-ray beam into a 16μm x 60μm spot in the next station, ID-D, where a broad range of x-ray spectroscopy techniques are used.

16ID-D: HPCAT director David Mao (front left), beamline scientists Yue Meng (front right) and Michael Hu (back right), and lead technician Eric Rod, preparing an x-ray emission spectroscopy experiment. The focused monochromatic x-ray beam impinges on the sample and the scattered photons are analyzed by a bank of crystals (in front of Eric) which re-focus the diverging photons onto a detector in the back-scattered geometry for the highest resolution. In this experiment David Mao and his team follow the low energy collective excitation of the electron gas in sodium metal as a function of pressure.

16ID-E: HPCAT project manager Daniel Häusermann completing the assembly of the 0.9m long horizontal focusing mirror before installation in ID-C. This custom-designed water-cooled silicon mirror achieves minimal mechanical and thermal strain operation and hence guarantees optimum performance in the highly challenging spectroscopy experiments. [ID-E is a large end station constructed for very-high-resolution phonon measurements, a future development of the HPCAT project. It is currently used as a clean-room for assembly of critical components.]

16BM-A: Beam-conditioning enclosure of the bending magnet beamline. In this station two sections of the 6mrad-wide x-ray fan from an APS bending magnet (BM) are selected and independently delivered to stations BM-B and BM-C/D. This gives the HPCAT BM line the unique capability of running two experiments in parallel.

16BM-B: Beamline control scientist Arun Bommannavar conducting final software tests on the high-energy diffractometer (left). The Perspex helium enclosure in front of Arun contains a two-mirror micro-focusing system for polychromatic radiation. Soon to be completed, the BM line will give HPCAT a unique capability for alternating polychromatic and monochromatic micro-diffraction from micron-size crystallites in ultr-high-pressure pow