Mini synchrotron to ease structural analysis?

Researchers are currently forced to use large synchrotron facilities to conduct protein crystallography experiments or analyse dense materials using radiography techniques. While there are an increasing number of these facilities around the world, getting time and funding to gain access to the facilities can still be a challenge that can slow vital research into the structure of proteins that may provide crucial information for drug development. The research, published in the journal Nature Physics​​ describes how a team led by Professor Dino Jaroszynski of the UK's Strathclyde University have managed to remove the need for giant particle accelerators when generating synchrotron light. Because the wavelength of visible light is longer than the length of an atomic bond microscopy techniques cannot be used to probe molecular structure and it is necessary to use radiation of shorter wavelength, such as x-rays. The use of x-rays to study the structure of crystals and materials is relatively commonplace, with most university chemistry departments having at least one 'benchtop' x-ray crystallography machines. However, to study complex structures such as enzymes large powerful x-ray sources are needed, and these are usually too large and too expensive for individual universities or companies to own. This leads to structural biologists having to book time at synchrotron facilities to be able to gather data on the structure of complex enzymes and proteins. At such facilities, large particle accelerators force electrons to move at high speeds and generate x-rays as they fly through the undulating magnetic field. Rather than relying on particle accelerators, the team has used a 'laser-plasma wakefield accelerator' that uses a high-intensity laser to generate waves in a plasma that accelerates electrons to high speeds. "The electrostatic forces of such a plasma wake (as found behind a boat) rapidly accelerate particles to very high energies,"​ write the authors. "Energy is gained analogously to a surfer acquiring momentum from a water wave." ​ These electrons then travel through a series of magnets known as an undulator that forces the electrons to collide and release the energy they have collected as electromagnetic waves. The authors state that compact radiation sources based on wakefield accelerators should have a number of advantages over conventional sources, including a vast reduction in size and cost. In addition, wakefield accelerators should enable "a wide range of applications such as time-resolved x-ray diffraction, photoelectron spectroscopy, ultrafast studies of material damage, plasma physics, radiography of dense materials and could produce a revolution in the way science is done." ​