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.
Figure: HPCAT’s compact, precision sample positioning system (left, shown with mounted diamond anvil cell) is used to rapidly collect two-dimensional intensity maps (center) from a sample chamber. Simultaneous collection of angle-dispersive x-ray diffraction images during the two-dimensional scan allows the researcher to accurately map the phase content of the sample chamber throughout the experiment. In this case, the x-ray diffraction image (right) comes from a small sphere – approximately 5 micrometers in diameter – of tantalum.