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December 15, 2016

Dedicated hardware and software for high-speed, high-precision scanning ‘on-the-fly’ have now been deployed at all of HPCAT’s end-stations.  More...

Dedicated hardware and software for high-speed, high-precision scanning ‘on-the-fly’ have now been deployed at all of HPCAT’s end-stations.  Hardware includes field-programmable gate array electronics with customizable logic circuits, allowing for accurate and precise sample position feedback based on encoder or step drive outputs. Custom control software has been written to enable high-speed, high-resolution sample mapping using x-ray transmission intensity while—with an appropriate area detector—simultaneously collecting angle-dispersive x-ray diffraction images.  Ongoing developments include novel data reduction techniques based on composite x-ray diffraction images from the noise-free Pilatus imaging detector.

 

December 15, 2016

Recently a new high-precision radioscope was designed, assembled, and commissioned at station 16-ID-B.   More...

Recently a new high-precision radioscope was designed, assembled, and commissioned at station 16-ID-B.  New features include a CCD camera with pixels one fourth the area of the previous cameras, a turning mirror incorporated within a conventional beamstop (allowing for simultaneous x-ray imaging and radial x-ray diffraction), and an ultrathin scintillator.  The overall design is compact and can be easy installed at any beamline using HPCAT’s existing motion control configuration for online optical systems.  The commissioning goal for the new radioscope was to measure minute strain applied to a sample in a diamond anvil cell by measuring the relative displacement of the diamond anvils (see radiograph below).  Commissioning results demonstrate a capability of measuring sub-micron compression and decompression strokes.  The compact design and high resolution make it possible to explore more advanced x-ray imaging techniques including, for example, tomogra

March 10, 2016

The on-line laser heating system has been reconfigured to accommodate the modification of the high energy monochromator at the 16-ID-B beamline. Several new items have been implemented in the reconfiguration.  More...

The on-line laser heating system has been reconfigured to accommodate the modification of the high energy monochromator at the 16-ID-B beamline. Several new items have been implemented in the reconfiguration. A new pair of 320 mm long focusing mirrors have been successfully installed in February 2016, which increases on-sample flux by a factor 2.5 compared to the previous setup. Currently, the focus beamsize is about 3x5 µm2. In the next cycle, another set of focusing mirrors will be installed for a focal size of 1x2 µm2. These two sets of mirrors are switchable in operation, as required by users’ experiments (prior arrangement and scheduling is required). A new beam-stop integrated with PIN diode for measuring transmitted x-ray intensity allows on-the-fly sample mapping with integrated x-ray diffraction. (Key personnel: Yue Meng, Ross Hrubiak, Eric Rod)

February 10, 2016

The 16-ID-B monochromotor has been modified to offer a significant increase in the maximum energy range up to 60 keV, and a substantial increase in flux at the nominal operating energy near 30 keV.  More...

The diffraction beamline (16-ID-B) monochromotor has been modified to offer a significant increase in the maximum energy range up to 60 keV, and a substantial increase in flux at the nominal operating energy near 30 keV. This was achieved by changing the offset of the branching IDB beamline from 1 m to 0.7 meters. The use of an air-bearing base table for holding the second monochromator crystal also increased the stability and reproducibility for tuning energies. The hutch reconfiguration and monochromator installation were completed in January 2016 and successful commissioning with x-rays was carried out in early February 2016, ready for users’ operation during the first beam cycle of 2016. Figure shows the new monochromator stand in place in the first optics enclosure, ready for final assembly.

December 15, 2015

HPCAT recently installed and commissioned a compact Kirkpatrick-Baez (KB) mirror assembly capable of delivering the smallest, most tightly focused beam yet at HPCAT’s General Purpose Table (16-ID-B).  More...

As we seek to explore the properties of materials under extreme conditions, the high pressure spectroscopy station (16-ID-D) has commissioned a new focusing mirror system.  Near the middle of December 2015, the entire 16-ID-D hutch was re-configured to accommodate the bendable KB mirrors coated with Rh and Pt stripes on well-polished silicon.  The mirrors in Kirkpatrick-Baez geometry consist of a 320 mm long upstream vertical mirror and a 400 mm long downstream horizontal mirror, with a working distance of 250 mm.  Also a versatile pinhole positioner was installed in order to provide clean beam. As a result, the focus size at 11.56 keV incident beam, was 2.3 µm vertical x 5.0 µm horizontal in FWHM, with measured throughput very close to the design values.  The micron-sized focus capability enables the spectroscopy station to extend the range of pressures to multiple megabars for spectroscopy measurements in diamond anvil cells.

October 23, 2015

HPCAT recently installed and commissioned a compact Kirkpatrick-Baez (KB) mirror assembly capable of delivering the smallest, most tightly focused beam yet at HPCAT’s General Purpose Table (16-ID-B).  More...

HPCAT recently installed and commissioned a compact Kirkpatrick-Baez (KB) mirror assembly capable of delivering the smallest, most tightly focused beam yet at HPCAT’s General Purpose Table (16-ID-B) (Fig. 6).  The approximate beam dimensions – characterized by the full-width half-maximum intensity (FWHM) of the derivative of knife edge across the focal spot – are 1 µm in the vertical direction and 2 µm in the horizontal direction.  The assembly is mounted on a precision rail system which allows robust, efficient switching between the large and small KB assemblies.  An integrated pinhole positioning system is mounted directly to the helium-filled enclosure, ensuring maximum stability of the pinhole with respect to the focused beam.  A range of clean-up pinhole sizes down to approximately 10 µm in diameter allows for maximum flexibility in the pinhole location with respect to various diamond anvil cell designs.

August 10, 2015

7-element analyzer for emission spectroscopy in ID-D -To improve collection efficiency in x-ray emission spectroscopy (XES) experiments, we have designed and commissioned a seven-element analyzer XES spectrometer at 16 ID-D.  More...

To improve collection efficiency in x-ray emission spectroscopy (XES) experiments, we have designed and commissioned a seven-element analyzer XES spectrometer at 16 ID-D of HPCAT. The spectrometer has seven 4-inch spherical bent analyzers arranged in a hexagonal pattern to make it compact and accommodate the opening of the most used 2-inch symmetric diamond anvil cells. Fluorescence from the sample is spectrally analyzed and reflected to a Pilatus 100K position sensitive detector by these analyzers. An emission spectrum is obtained by rotating the analyzer Δϑ, tracked by the corresponding 2Δϑ rotation of the detector. Bending radius of all analyzers is one-meter, with seven analyzers, the spectrometer covers a solid angle of ~56msr. This new spectrometer collects a similar solid angle compared to miniXES and polycapillary lens spectrometer and still keeps an energy resolution of ~1eV.

July 25, 2015

On-the-fly sample mapping with integrated x-ray diffraction - HPCAT recently developed and commissioned a compact, high precision, high speed sample positioning system.  More...

HPCAT recently developed and commissioned a compact, high precision, high speed sample positioning system.  The core components of the system include four precision DC servomotor stages with encoder resolutions ranging from 50 to 100 nm.  Sample motion profiles are executed by an advanced motion control system that uses real-time positioning feedback for accurate, on-the-fly triggering of external hardware components, viz., imaging detectors and photon counters.

December 21, 2014

We have developed a technique for studying oxide-and-water interfaces under hydrothermal conditions up to 350 °C and 20 MPa.   More...

We have developed a technique for studying oxide-and-water interfaces under hydrothermal conditions up to 350 °C and 20 MPa. In-situ high-resolution x-ray reflectivity (HRXR) under such condition can provide unique information of interfacial hydration, ion adsorption, and dissolution/growth/alteration processes on the metal-oxide surfaces with molecular scale resolution (typically less than 0.1 nm) which are crucial to understanding the fundamentals related to materials integrity in the nuclear power plant conditions. The prototype cell has been designed and pilot tested. This is the first of this kind, and gives us a unique position leading the in-situ hydrothermal study of solid-water interface processes.

April 29, 2014

A laser drill system has been recently constructed and made operational for routine use at HPCAT since February 2014. The new drill system uses a pulsed laser of 400ps pulse duration, ablating materials without thermal melting, thus leaving a clear edge after drilling.   More....

A laser drill system has been recently constructed and made operational for routine use at HPCAT since February 2014. The new drill system uses a pulsed laser of 400ps pulse duration, ablating materials without thermal melting, thus leaving a clear edge after drilling. With optics designed for a tight focus, the drill machine can drill any size holes of larger than 3 microns in diameter. The capability of drilling small holes in gaskets is important for ultrahigh pressure experiments. Unlike standard EDM drill machine, the new laser drill system allows drilling non-conductive materials such as amorphous boron and silicon carbide gaskets, diamond, oxides and many other materials including organic materials (e.g. kapton). The machine can also be used for sample cutting and for making engineered sample environments (e.g. cutting insulation plates critical for laser-heating experiments).