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1.
Appl Opt ; 57(18): 5004-5010, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-30117959

RESUMO

A new generation of cameras has made ultra-high-speed x-ray imaging at synchrotron light sources a reality, revealing never-before-seen details of sub-surface transient phenomena. We introduce a versatile indirect imaging system capable of capturing-for the first time-hundreds of sequential x-ray pulses in 16-bunch mode at the European Synchrotron Radiation Facility, recording at 5.68 Mfps over dozens of microseconds, with an effective exposure of 100 ps. The versatile multiplex camera construction of the system allows for various arrangements, including different scintillator configurations, and simultaneous imaging with different resolutions and regions of interest. Image results from a gas gun impact experiment, in which an additive manufactured aluminum lattice was dynamically compressed, is presented as a demonstration of the system's capabilities.

2.
J Synchrotron Radiat ; 23(Pt 3): 685-93, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27140147

RESUMO

The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits).

3.
Sci Rep ; 7: 45206, 2017 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-28555619

RESUMO

Chondritic meteorites are fragments of asteroids, the building blocks of planets, that retain a record of primordial processes. Important in their early evolution was impact-driven lithification, where a porous mixture of millimetre-scale chondrule inclusions and sub-micrometre dust was compacted into rock. In this Article, the shock compression of analogue precursor chondrite material was probed using state of the art dynamic X-ray radiography. Spatially-resolved shock and particle velocities, and shock front thicknesses were extracted directly from the radiographs, representing a greatly enhanced scope of data than could be measured in surface-based studies. A statistical interpretation of the measured velocities showed that mean values were in good agreement with those predicted using continuum-level modelling and mixture theory. However, the distribution and evolution of wave velocities and wavefront thicknesses were observed to be intimately linked to the mesoscopic structure of the sample. This Article provides the first detailed experimental insight into the distribution of extreme states within a shocked powder mixture, and represents the first mesoscopic validation of leading theories concerning the variation in extreme pressure-temperature states during the formation of primordial planetary bodies.

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