By blasting plasma in their tabletop-size laser-plasma accelerator, the scientists assert that they have produced acceleration energy of around of 4.25 giga-electron volts. Acceleration of this magnitude over the short distances involved correlates to an energy rise 1,000 times greater than that of a traditional – and very much larger – particle accelerator.

The Large Hadron Collider (LHC) at CERN, for example, is some 17 miles (27 km) in circumference, and accelerates particles by way of a series of sequential, modulated electromagnetic fields contained in a metal cavity. This is perfectly fine for anything up to about 100 mega-electron volts per meter before things go awry and the metal cavity starts to break apart.

By comparison, the tiny Berkeley Lab accelerator achieves its world record by accelerating electrons inside a plasma tube just 9 cm (3.5 in) long up to a speed that would normally take an average particle accelerator many, many miles to achieve (if at all), and in a unit that sits comfortably on the top of a laboratory table.