Physicists from the A-SAIL Project have demonstrated a novel technique for simultaneously accelerating and collimating laser-driven ions.
A new paper from Dr Satyabrata Kar and colleagues published in Nature Communications, sets out the details of a proof-of-principle experiment showing how ions, driven from a foil by a laser pulse, can be accelerated further using a coil. Moreover, the technique also has the advantage of collimating the beam, and favouring certain energy bands.
The results, the authors say, “open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications”.
Dr Kar said: “There has been increasing interest in laser-driven ion acceleration, whereby you produce a burst of ions by shooting a thin foil with an intense laser. But one problem is that the beam spreads out, spatially and in terms of the range of energies produced. The technique we have developed simultaneously directs the beam in a column, selects a tighter range of energies, and accelerates the ions even after they have left the foil”.
The coil set-up constitutes a versatile miniature linear accelerating device, and one which can be multi-staged for enhanced performance. That is, by arranging two of the coils in sequence the booster effect can be virtually doubled.
The rate of energy increase and beam guiding achieved with the coil could prove a significant development for areas such as radiobiology, helping to bring laser-driven proton beam therapy a step closer.
The research involved collaboration across a number of institutions, and was part-funded by the A-SAIL Program grant, an EPSRC-funded effort to lay the groundwork for the next generation of radiation therapies.
The results were published in Nature Communications, 18 April 2016.
S Kar et al, Guided post-acceleration of laser-driven ions by a miniature modular structure,
Nature Communications 7, Article number: 10792 doi:10.1038/ncomms10792