First, a packet of protons from CERN's proton accelerator, the Super Proton Synchrotron, will pass through a field of plasma. The electrons in the plasma are negatively charged, so they fly towards the positively charged proton bunch. By that point, though, the protons have flown away, so the electrons keep flying. The electrons leave positively charged plasma in their absence, though, so they're pulled back to where they came from. The process continues and makes a wave. If you plop another electron into the wave, it will surf along to avoid all the other negative electrons crashing down, causing our surfer dude to accelerate really quickly through the wake field, as much as a thousand times faster than the traditional method, according to an article published in Nature.