L2A2

Laser-plasma acceleration is a promising technology enabling the construction of compact particle accelerators for fundamental and applied research. Ultra-intense ultra-short laser pulses focused in few square microns on a micrometric material layer generate electric fields, thousand times more intense than those produced with radio frequency cavities, where electrons are accelerated at relativistic energies. The electron cloud, leaving the target material, ionizes the atoms at the surface and creates an intense electric gradient where ions are accelerated, in particular the lighter ones, protons.

On top of its intrinsic interest, IGFAE researchers also identified laser-plasma acceleration as an opportunity to transfer the knowledge generated through its participation in large-scale international experiments. Those were the motivations to promote the construction of the Laser Laboratory for Acceleration and Applications (L2A2). This is a research infrastructure at the University of Santiago de Compostela hosting a 50 TW laser system and a radio-protected area for laser-plasma particle acceleration experiments.

The research program led by IGFAE at L2A2 focuses on medical applications of laser-accelerated particles. At present this program concentrates in two initiatives: laser-driven production of radio-isotopes for PET imaging (LaserPET) and new laser-driven X-ray sources and their application in imaging (LaseX).

LaserPet

The aim of the project is to develop the technology required for the competitive production of radioisotopes used in positron-emission tomography (PET) by using laser-particle accelerators. The main argument is that present technologies for the production of PET isotopes are based on a centralized production and distribution scheme because of the rather large cost of the infrastructure required. Compact laser-accelerators could become the enabling technology for the on-demand production of PET radioisotopes, opening the possibility of using short-lived isotopes, such as 11C, 13N or 15O, of special interest for the diagnostic of neurodegenerative and cardiovascular diseases.

LaseX

Low-energy laser pulses produced at L2A2 (1 mJ, 25 fs, 1kHz), efficiently focused (~ 10 μm2) on different target materials, generate a plasma where electrons are accelerated up to some tens of kiloelectronvolts. The interaction of these electrons with the same target material generates X-rays within the same range of energies. The advantage of these new X-ray sources, with respect to conventional ones, is the micrometric size of the focus. Under such conditions one can produce X-ray images with much better quality and lower doses. Moreover, one can also produce images not only based on the simple absorption technique, but also taking advantage of the phase of the produced X-rays, the so-called “phase-contrast imaging”. This technology provides an additional sensitivity to the density of the exposed object, which is particularly interesting for biological samples.