Lasers and synchrotron light sources have become ubiquitous tools for time-resolved probing of the composition and structure of matter. Governments are prepared to meet their significant costs because they are the scientific tools for research and development which underpin progress in society.Investigations of molecular and solid structure require x-rays from today’s powerful synchrotrons and free-electron lasers (FELs). These modern light sources are based on particle accelerator technology which makes them very large, with areas equivalent to several football pitches, and very expensive, with their construction alone costing hundreds of millions of Euros. Until now, light sources have been driven by accelerators based on microwave cavities. This conventional technology is not the only way to accelerate particles. Researchers at the University of Strathclyde have led an international project in collaboration with Oxford and Berkley which has pioneered a new way of accelerating particles using lasers and used these particles in the first demonstration of a table-top synchrotron source.
Electrostatic forces of plasma, which is fully ionised gas, can be harnessed to provide vastly higher accelerating gradients for charged particles. By firing an intense laser pulse from a table¬top terawatt ultra-sort pulse laser into plasma, a density wake similar to that behind a boat on water can be excited. The huge electric fields inside the plasma provide immense forces to accelerate electrons to very high energies over a few millimetres whereas accelerator conventional technology would require 10’s to 100’s of metres to achieve the same energy. Small bunches of electrons from the background plasma surf down the wake wave and rapidly acquire kinetic energy from the wave, just like a surfer catches a wave and gains energy from it to accelerate forward. The excellent properties of electron beams produced from these so-called plasma wakefield accelerators provides an opportunity to build ultra-compact femtosecond light sources. Thus these table-top devices could herald a revolution in the way science and technology is done – by making available compact sources at a fraction of the cost of large facilities.
Both particles and high energy x-rays from wakefield accelerators would be ideal in the development of advanced detectors for medicine and nuclear and particle physics.The laser-driven accelerator and radiation source developments will result in knowledge transfer both directly by providing unique Scottish based facilities and through the direct development and commercialisation of the sources which have the prospect of being installed in University sized institutions.
A patent on a compact radiation source has been filed in collaboration with Oxford and Berkeley National Laboratory.
For further information, please contact Research & Knowledge Exchange Services:e: rkes@strath.ac.uk t: 0141 548 3707 f: 0141 552 4409