A5049842367- Advanced X-ray Imaging Techniques
- Medical Imaging Techniques and Applications
- Advanced Optical Sensing Technologies
- Enzyme Structure and Function
- Analytical Chemistry and Sensors
- Particle Detector Development and Performance
- CCD and CMOS Imaging Sensors
- Advanced Electron Microscopy Techniques and Applications
- Advanced X-ray and CT Imaging
- X-ray Spectroscopy and Fluorescence Analysis
- Cultural and political discourse analysis
- Additive Manufacturing and 3D Printing Technologies
- Advancements in PLL and VCO Technologies
- Agricultural and Food Production Studies
- Computational Physics and Python Applications
- International Relations in Latin America
- Biosensors and Analytical Detection
- Intermetallics and Advanced Alloy Properties
- Crystallography and Radiation Phenomena
- Advanced Fluorescence Microscopy Techniques
- Wireless Power Transfer Systems
- Porphyrin Metabolism and Disorders
- Chemical and Physical Properties of Materials
- Monoclonal and Polyclonal Antibodies Research
- Metallic Glasses and Amorphous Alloys
University of St. Thomas - Minnesota
2018-2024
University of Houston
2021
University Hospital Heidelberg
2021
Heidelberg University
2021
Cornell University
2007-2012
Johns Hopkins University Applied Physics Laboratory
2012
Institut Laue-Langevin
2008
Korea Atomic Energy Research Institute
2008
SPring-8
2008
Japan Synchrotron Radiation Research Institute
2008
Size Matters Less X-ray crystallography is a central research tool for uncovering the structures of proteins and other macromolecules. However, its applicability typically requires growth large crystals, in part because sufficient number molecules must be present lattice sample to withstand x-ray—induced damage. Boutet et al. (p. 362 , published online 31 May) now demonstrate that intense x-ray pulses emitted by free-electron laser source can yield data few enough exposures uncover...
We have used self-propagating exothermic reactions in Al/Ni multilayers as a means to explore the effect of rapid heating on phase transformations. Using time-resolved synchrotron x-ray microdiffraction with an extremely fast detector, we were able examine reaction sequence detail at rates ∼106 K s−1. observed that intermediate phases formed during are different from those lower rates, even though final same. In situ characterization is essential, other studying (such quenching followed by...
We showed how intermetallic formation reactions can be studied under rapid heating (106–107 K s−1) using x-ray microdiffraction with temporal resolution on microsecond time scales. Rapid was achieved by initiating an exothermic reaction in multilayer foils comprising alternating nanoscale layers of elemental metals. The occurred a front ∼100 μm wide which propagated across the foil at ∼1–10 m s−1. By synchrotron x-rays focused to small spot (60 diameter) and fast pixel-array detector, we...
The production of high-performance carbon nanotube (CNT) materials demands understanding the growth behavior individual CNTs as well collective effects among CNTs. We demonstrate first use grazing incidence small-angle X-ray scattering to monitor in real time synthesis CNT films by chemical vapor deposition. a custom-built cold-wall reactor along with high-speed pixel array detector resulting resolution 10 msec. Quantitative models applied time-resolved patterns reveal that Fe catalyst film...
Direct time-of-flight (dToF) sensors that measure depth by pulsing a laser and timing the photon return are used in many applications, including consumer electronics for proximity sensing map generation. A histogram of times is measured then processed to estimate object depth. By collecting photons span multiple bins final interpolates between time-to-digital converter (TDC) produce result more precise than resolution. The precision this interpolation depends on temporal spread measurement,...
Test results are presented of a pixel array detector (PAD) developed for x-ray imaging at the Stanford Linear Coherent Light Source (LCLS). The basic module PAD consists two bump-bonded chips: reverse-biased silicon diode chip 185 × 194 pixels, each which is coupled by bump-bonds to charge integrating CMOS ASIC with digitization in pixel. LCLS experiment requires high signal-to-noise ratio detection single 8 keV x-rays, full-well exceeding 1,000 frame-rate 120 Hz, and ability handle arrival...
A pixel array detector (PAD) module has been developed at Cornell University for the collection of diffuse diffraction data in anticipation coherent X-ray imaging experiments that will be conducted Linac Coherent Light Source (LCLS) SLAC National Accelerator Laboratory. The is designed to collect X-rays scattered from monochromatic femtosecond pulses produced by LCLS laser framing rates up 120 Hz. Because arrive on time scales, must able deal with instantaneous count-rates excess 1017...
The "IRE Standards on Piezoelectric Crystals-The Vibrator" specifies nomenclature and methods of measurement the various quantities associated with piezoelectric vibrators. This paper gives in detail theoretical considerations these measurements, which are based frequency maximum transmission through a simple pi resistance network includes vibrator series arm. motional resonance value by substitution resistor place may be obtained from measurement. take into account stray capacitances other...
Dynamic X-ray studies can reach temporal resolutions limited by only the pulse duration if detector is fast enough to segregate synchrotron pulses. An analog integrating pixel array with in-pixel storage and resolution of around 150 ns, sufficient isolate pulses, presented. Analog integration minimizes count-rate limitations captures successive Fundamental tests noise linearity as well high-speed laser measurements are shown. The resolved individual bunch trains at Cornell High Energy...
Tools that standardize and automate experimental data collection are needed for greater confidence in research results. The National Synchrotron Light Source-II (NSLS-II) has generated an open-source Python acquisition, management, analysis software suite automates X-ray experiments collects record facilitates complete reproducibility. Here, we show the NSLS-II tools not only useful science at large-scale facilities by presenting add-on package adapts these use a small laboratory with common...
A Mixed-Mode Pixel Array Detector has been developed to measure protein crystallographic diffraction patterns. X-rays are stopped in a 500 μm thick layer of silicon diodes, and collected charge is processed by an attached ASIC. Goals the project high flux (10<sup>8</sup> x-rays/s/pixel) capability fast readout (< 0.5 ms dead time between frames). "Mixed-Mode" refers method whereby integrated signal accumulating each pixel compared against threshold value. When reached, digital count added...
We describe the development of a CMOS read-out chip for an X-ray pixel array detector that accumulates into analog storage elements with time resolution typical synchrotron bunch spacings. Each contains multiple to allow capture full-frame images at submicrosecond separation. Additionally, each element is re-addressable, which allows accumulation signal from temporally distinct acquisition windows. Test results show ability slew and settle equivalent 650 8-keV x-rays (1.21 Me <sup...
A pair of techniques have been developed for performing time-resolved X-ray microdiffraction on irreversible phase transformations. In one technique capillary optics are used to focus a high-flux broad-spectrum beam 60 µm spot size and fast pixel array detector is achieve temporal resolution 55 µs. the second X-rays focused with Kirkpatrick-Baez mirrors spatial better than 10 shutter provide 20 µs while recording diffraction pattern (relatively slow) CCD camera. Example data from experiments...
We demonstrate a methodology for non-contact classification of five different plastic types using an inexpensive direct time-of-flight (ToF) sensor, the AMS TMF8801, designed consumer electronics. The ToF sensor measures time brief pulse light to return from material with intensity change and spatial temporal spread returned conveying information on optical properties material. use measured histogram data all plastics, captured at range distances, train classifier that achieves 96% accuracy...
Ultrasonic sensors have dominated miniaturized depth measurement applications such as robot collision avoidance and walking cane hazard detection yet limited spatial resolution. Optical time-of-flight (ToF) offer the potential for improved resolution, however, ToF depth-sensing cameras may be too large power-hungry hand-held applications. We address this gap by experimentally evaluating an infrared sensor (the ST VL53L1X) that uses a single-photon avalanche photodiode array to provide coarse...
An imaging Pixel Array Detector (PAD) is being developed to record x-ray scattering images from single particles at the SLAC Linac Coherent Light Source (LCLS) free electron laser. The LCLS will deliver pulses of 5-200 femtosecond duration 120 times per second. Proposed experiments require that scatter each pulse be independently recorded. This necessitates a detector with charge integrating front-end because high instantaneous arrival rate photons (> 1000 pixel in femtoseconds) exceeds...
A low-pressure direct injection fuel system for spark ignition engines has been developed, in which a high-turbulence nozzle technology was employed to achieve fine droplet size at low pressure around 2 MPa.It is particularly important study spray characteristics the nearnozzle region due immediate liquid breakup exit.By using an ultrafast x-ray area detector and intense synchrotron beams, interior structure dynamics of gasoline sprays from multi-orifice turbulence-assisted were elucidated...
Solution small-angle X-ray scattering (SAXS) measurements were obtained using a 128 × pixel mixed-mode array detector (MMPAD) with an 860 µs readout time. The MMPAD offers advantages for SAXS experiments: full-well of >2 10(7) 10 keV X-rays, maximum flux rate 10(8) X-rays pixel(-1) s(-1), and sub-pixel point-spread function. Data from the quantitatively compared data charge-coupled device (CCD) fiber-optically coupled to phosphor screen. solution lysozyme solutions equal or better quality...
A data Acquisition (DAQ) and control system is being developed for a pixel array detector that will be used single-particle scattering experiment at the linac coherent light source (LCLS). The requires sub-picosecond pulses of 8 kEV X-rays are scattered off single particles 120 times second. converted to charge in 2-dimensional pixelated diode array. integrated on 760times760 readout chip digitized in-pixel. full composed tiled 185times192 chips. DAQ provides low-level integration read-out...
We describe a custom and open source field-programmable gate array (FPGA)-based data acquisition (DAQ) system developed for electrophysiology generally useful closed-loop feedback experiments. FPGA processing are combined with high-speed analog digital converters to enable real-time feedback. The approach eases experimental setup repeatability by allowing identification in situ tuning of filter bandwidths. includes I2C serial peripheral interface controllers, 1 GiB dynamic RAM buffering,...