Ultrafast X-rays: ‘Dusty mirror’ gets a makeover
Inspired by an old optics experiment carried out by Isaac Newton, researchers have devised a scheme to study microscopic particles with intense ultrafast X-ray pulses. It’s thought this type of X-ray ‘flash’ imaging may be used to explore the three-dimensional dynamics of materials at the timescale of atomic motion.
Newton was puzzled by the circular patterns that appeared when he illuminated a silver-plated mirror. As it turned out, this was caused by interference between two paths of light scattering from dust particles on the front of the mirror — one path of light on its way towards the mirror, and one reflecting from the silvered surface. In this week’s Nature, Henry N. Chapman and colleagues describe a modern, more dynamic version of this ‘dusty mirror’ experiment that uses X-rays.
The team fired their ultrafast light source at a thin membrane containing polystyrene particles placed in front of a mirrored backplate. The incident X-rays cause the polystyrene particles to explode, and they then hit the polystyrene particles a second time as they are reflected back from the mirrored plate. The resulting interference pattern can be used to retrieve information about the polystyrene particles with high time and space resolution.

CONTACT

Henry N. Chapman (Lawrence Livermore National Laboratory, Livermore, CA, USA)
Tel: +1 925 423 1580; E-mail: henry.chapman@llnl.gov

Andrea Cavalleri (University of Oxford, UK) N&V author
Tel: +44 1865 272 365; E-mail: a.cavalleri1@physics.ox.ac.uk