Particle acceleration based on high intensity laser systems (a process known as laser-plasma acceleration) has achieved high quality particle beams that compare favourably with conventional acceleration techniques in terms of emittance, brightness and pulse duration. A long-term difficulty associated with laser-plasma acceleration--the very broad, exponential energy spectrum of the emitted particles--has been overcome recently for electron beams. Here we report analogous results for ions, specifically the production of quasi-monoenergetic proton beams using laser-plasma accelerators. Reliable and reproducible laser-accelerated ion beams were achieved by intense laser irradiation of solid microstructured targets. This proof-of-principle experiment serves to illuminate the role of laser-generated plasmas as feasible particle sources. Scalability studies show that, owing to their compact size and reasonable cost, such table-top laser systems with high repetition rates could contribute to the development of new generations of particle injectors that may be suitable for medical proton therapy.

Ultrashort light pulses are powerful tools for time-resolved studies of molecular and atomic dynamics1. They arise in the visible and infrared range from femtosecond lasers2, and at shorter wavelengths, in the ultraviolet and X-ray range, from synchrotron sources3 and free-electron lasers4. Recent progress in laser wakefield accelerators has resulted in electron beams with energies from tens of mega-electron volts (refs 5,6,7) to more than 1 GeV within a few centimetres8, with pulse durations predicted to be several femtoseconds9. The enormous progress in improving beam quality and stability5, 6, 7, 8, 10 makes them serious candidates for driving the next generation of ultracompact light sources11. Here, we demonstrate the first successful combination of a laser-plasma wakefield accelerator, producing 55-75 MeV electron bunches, with an undulator to generate visible synchrotron radiation. By demonstrating the wavelength scaling with energy, and narrow-bandwidth spectra, we show the potential for ultracompact and versatile laser-based radiation sources from the infrared to X-ray energies. (Abstract from: http://www.nature.com/nphys/journal/v4/n2/abs/nphys811.html

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Innovation studies continue to struggle with an apparent disconnect between innovation's supposedly universal dynamics and a sense that policy frameworks and associated instruments of innovation are often ineffectual or even harmful when transported across regions or countries. Using a cross-country comparative analysis of three implementations of the 'MIT model' of innovation in the UK, Portugal and Singapore, we show how key features in the design, implementation and performance of the model cannot be explained as mere variations on an identical solution to the same underlying problem. We draw on the concept of sociotechnical imaginaries to show how implementations of the 'same' innovation model -and with it the notion of 'innovation' itself -are co-produced with locally specific diagnoses of a societal deficiency and equally specific understandings of acceptable remedies. Our analysis thus flips the conventional notion of 'best-practice transfer' on its head: Instead of asking 'how well' an innovation model has been implemented, we analyze the differences among the three importations to reveal the idiosyncratic ways in which each country imagines the purpose of innovation. We replace the notion of innovation as a 'panacea' -a universal fix for all social woes -with that of innovationas-diagnosis in which a particular 'cure' is 'prescribed' for a 'diagnosed' societal 'pathology,' which may in turn trigger 'reactions' within the receiving body. This approach offers new possibilities for theorizing how and where culture matters in innovation policy. It suggests that the 'successes'