A laser beam (red,
coming from the left) shines on an ultrathin diamond-like carbon foil
coated on one side
with a layer of nanotubes. The impact of the laser beam ejects
high-energy ions from
the uncoated side of the carbon foil. The additional focus
provided by the
nanotube coating enhances the efficiency of this laser-driven
particle
acceleration. Illustration: Isabella Cortrie
(August 4, 2015) An
international team of physicists has used carbon nanotubes to enhance the
efficiency of laser-driven particle acceleration. This significant advance
brings compact sources of ionizing radiation for medical purposes closer to
reality.
The interaction of high-intensity laser light with solid
targets could someday serve as the basis of table-top sources of high-energy
ions for medical applications. An international team led by physicists of the
LMU affiliated with the Munich-Centre for Advanced Photonics (MAP), a Cluster
of Excellence based in Munich, and in cooperation with scientists from the Max
Planck Institute of Quantum Optics, has taken another step towards this goal.
They have done so by boosting the efficiency of a technique that uses extremely
intense pulses of laser light to eject packets of high-energy ions from diamond-like
carbon foils. In their experiment, the researchers coated one side of the foil
with carbon nanotubes. Upon laser irradiation, the layer acts like a lens to
focus and concentrate the light energy on the foil, which results in the
production of much more energetic ion beams. This makes experiments with
high-energy carbon ions on cells feasible for the first time, and brings
light-driven generation of ionizing radiation closer to practical
application.