Researchers used one of the most powerful lasers in the world to accelerate subatomic particles to the highest energy ever recorded from a compact accelerator.

The particle reached its record-breaking speed using a petawatt laser and a charged-particle gas called plasma, DOE/Lawrence Berkeley National Laboratory reported. Plasma accelerators are usually miles long, but an emerging class called laser-plasma accelerator could potentially be shrunk down to be small enough to fit on a table.

In the recent experiment electrons were sped up inside a 9-centimeter-long tube of plasma. The speed corresponded to an energy of 4.25 giga-electron volts, this

"This result requires exquisite control over the laser and the plasma," said Wim Leemans, director of the Accelerator Technology and Applied Physics Division at Berkeley Lab and lead author on the paper. The results appear in the most recent issue of Physical Review Letters.

Traditional particle accelerators, such as the 17-mile-long Large Hadron Collider at CERN (the European Union Organization for Nuclear Research), speed up particles by modulating electric fields, but the technique has a limit of about 100 mega-electron volts per meter before the metal is degraded. Laser-plasma accelerators, on the other hand, use a pulse of laser light that is injected into a plasma tube. The technique creates waves that trap free electrons and accelerate them to high energies.

"It is an extraordinary achievement for Dr. Leemans and his team to produce this record-breaking result in their first operational campaign with BELLA," said James Symons, associate laboratory director for Physical Sciences at Berkeley Lab.

To accelerate the electrons to higher energies in the future the researchers will need to more precisely control the density of the plasma channels through which the laser channels are directed. In order to do this the researchers will have to create a tunnel for the light pulse that is the perfect shape to handle more energetic electrons.